Jasper Ridge Biological Preserve, Stanford University: Some Native and Naturalized Grasses

2010-07-19T16:17:00.000-07:00

Jepson Herbarium Poaceae Workshop at Jasper Ridge (May 2010)
Instructor Travis Columbus

http://www.flickr.com/photos/tcorelli/sets/72157624086917934/

2009-05-15T09:46:00.000-07:00

May 6, 2009. Vulpia octoflora var. hirtella. A collection was made at the sharp turn on trail 9. JH Thomas' 1958 collection of Vulpia octoflora v. octoflora, recently re-determined to Vulpia octoflora var. hirtella, was from the Escobar Gate area.

Also blooming on trail 9 were several Phacelia rattannii, Cryptantha clevelandii (several spots), C. micromeres (near the Vulpia octoflora). C. micromeres is also blooming on the Rattlesnake Rock trail. Sunday evening on Rd E approaching the big inlet from the downhill side I collected the single-nutleted Cryptantha microstachys. C. flaccida is still in bloom on serpentine. Just west of the Vulpia octoflora var. hirtella before the Sanicula laciniata site and the beginning of Buckeye alley, about 30 purported Githopsis specularioides were in bloom on the uphill side of the trail. They were photographed but no collection was made. The plants were gone when a collecting party returned to the site two weeks later. Hesperolinom micranthum was blooming in the same area (also in trail 11 in chaparral). Linanthus pygmaeus ssp. continentalis was also blooming on trail 11 at its usual spot. Several tiny plants of Heterocodon rariflorum were in fruit on trail 10 at the edge of chaparral along with Yabea microcarpa, Daucus pusillus, Linanthus bicolor, and Pectocarya pusilla.

photo above: Vulpia octoflora. Photo by Toni Corell.
photo left: Linanthus pygmaeus ssp. continentalis. Photo by Toni Corell.

2008-12-14T16:33:00.000-08:00

A walk in Jasper Ridge's serpentine prairie, an article appearing in Grasslands, Spring 2008. Correction: A.G. Vestal was a member of Stanford's Biology Dept., not a Carnegie Institution research scientist. Photo by Toni Corelli.

2008-11-06T17:54:00.000-08:00

Quercus cf. berberridifolia Liebm. (syn in part Quercus dumosa Nutt.)
There is an entity occasional on the Ridge, always a low shrub to 3 ft. tall, sometimes in groups of a few individuals, sometime single, usually on northern slopes 500-600 feet elevation. We have never observed acorns. The leaves are adaxially ± flat to wavy, ± shiny, green, abaxially pale green, margin mucro- or spine-toothed. We have occasioanlly noticed the adaxial leaf feature emphasized in Jepson II: "with minute appressed stellate hairs." Collections of several individuals have been made, and some plants in the field are marked with green tape.

Treatment in Jepson 2 by the late John Tucker

Q. berberidifolia Liebm.
Shrub 1-3 m or ± tree > 3 m, evergreen. LF: 1.5-3 cm; petiole 2-4 mm; blade oblong, elliptic, or ± round, adaxially ± flat to wavy, ± shiny, green, abaxially with minute appressed stellate hairs, dull, pale green, tip gen rounded, margin mucro- or spine-toothed. FR: cup 12-20 mm wide, 5-10 mm deep, hemispheric to bowl-shaped, thick, scales tubercled; nut 10-30 mm, gen ovoid, tip obtuse to acute, shell glabrous inside; mature yr 1. Dry slopes, chaparral; 100-1800 m. KR, NCoR, CaRH, SNF, Teh, ScV (Sutter Buttes), CW, SW; Baja CA. Hybrids with Quercus durata, Quercus engelmannii, Quercus garryana (Quercus howellii J.M. Tucker), Quercus john-tuckeri, Quercus lobata.

Local references to Q dumosa

Q. dumosa was reported by Cooper (1922, p.26) as a constituent of the climax chaparral association on Jasper Ridge. His research area was just south of the current southern boundary of the Preserve. Other oaks in this association were gold cup, leather (Q. durata), interior live. He notes that all are evergreen, except the Q. dumosa is barely so. He also lists Castanopsis chrysophylla (Chrysolepis chrysophylla) as important. Where has it gone?
The Preserve?s first plant list (Springer, 1935) doesn't list Q. dumosa. It does include Quercus sp., found in the chaparral.
Duncan Porter (1962) lists Q. dumosa and indicates that is was vouchered in the Dudley Herbaium (voucher # 100665). This voucher was later redetermined as Q. durata.
Dengler (1973-74) does not list Q. dumosa though he lists a number of hybrids [Q kellog x Q. wiz (morehus); Q. agrifolia x Q. wizlizenii; Q. agrifolia x Q. kellog; Q. doug x Q. lobata; Q doug x Q. durata]. The latter was confirmed by John Tucker.
There are transcribed lecture notes of Mooney, HA. 1978-1979 "Jasper Ridge Plant Communities [Lecture Notes]", which make reference to seven oaks at JR and a specific example in the field of Q. dumosa.

Cooper, William. 1922. The broad-sclerophyll vegetation of California: an ecological study of chaparral and its related communities . Washington, D.C.: Carnegie Institution of Washington.
Porter, Duncan 1962. The vascular plants of the Jasper Ridge Biological Experimental Area of Stanford. Dept. Biol. Sciences. Research Report no. 2.

2008-11-03T13:04:00.000-08:00

Slender false brome,
Brachypodium sylvaticum.

One plant discovered on preserve near Sandhill Rd. in 2007. Extirpated. This distinctive perennial forest grass has sessile spikelets, long-awned lemmas, and densely hairy nodes. It has naturalized and is locally abundant in Huddart Park (San Mateo County) and MPROSP Thornewood Preserve and adjacent private land.

See California Invasive Plant Council plant profile http://www.cal-ipc.org/ip/management/plant_profiles/Brachypodium_sylvaticum.php

2007-10-15T13:39:00.000-07:00

Reduction of exotic grasses in serpentine

Lolium multiflorum has become a dominant plant in portions of Jasper Ridge's serpentine prairie over the past three decades. A variety of discussions in April 2007 led to a suggested experiment in area H of the serpentine grassland (see map) to try and reduce exotic grasses. Based on the experience of Stu Weiss at Edgewood Park, and others elsewhere, there is evidence that mowing of grasses can help increase population densities of the food plants of the Bay checkerspot butterfly in the year following mowing.

Proposal: mowing at 6" height without followup raking because raking had no additional effect in Weiss' studies; mowing closer to the ground, and perhaps raking as well, would likely impact arthropods and herps. Based on Richard Hobbs' observation that late summer rain appears to trigger germination of grasses much more than forbs, and, if followed by a month of dry weather, cause a false start to the growing season, we are suggesting a watering treatment in August. The water would be applied via some type of soaker hose from a water truck (to deliver 1cm of water would take a couple of trips with the water truck).

These two treatments should be compared with controls and replicated 4 times in an area near a fire road. Each plot will be 3m x 10 or 15m, with 12 plots total, and buffers between plots.

Area H Mow Area Plant List; choose Area H work sheet. This plant list was compiled by the Herbarium crew walking through the proposed site on May 2, 2007.

2007-08-27T09:29:00.001-07:00

Newly proposed checkerspot critical habitat

The new US Fish and Wildlife proposal for Bay checkerspot critical habitat is a modification of the critical habitat outlined in 2001 (which was sent back to F&W by a lawsuit). A final determination will be made by Aug 14, 2008.

Changes in the critical habitat were made based on decisions about the physical and biological features that are essential to the conservation of the butterfly. Some areas that are non-grassland or extensively developed
were dropped, while a Pulgas Ridge unit was added because it historically supported the Bay checkerspot and could be a stepping stone between the San Bruno Mountain unit and the southern San Mateo County units (Edgewood Park
and Jasper Ridge). In total, the current proposed area is smaller than the 2001 rule by about 4,000 acres, and includes 329 acres (133 ha) at Jasper Ridge.

The following website includes a link to the Federal Register with the revised proposal, which has a fairly detailed discussion of the revised critical habitat units.
http://www.fws.gov/sacramento/ea/news_releases/2007%20News%20Releases/BCB_2007_pCH_revision_NR.htm

Nona Chiariello

2006-04-04T08:30:00.000-07:00

Some naturalized annuals

Many of the annual grasses that dominate California valley and foothill grasslands grow in the vicinity of the Preserve's Escobar Gate. At arm’s length, with practice, all should be recognizable to genus and some to species. The underlying rock is sandstone, and the grasses include slender wild oat (Avena barbata), soft chess (Bromus hordeaceus), Spanish brome (B. madritensis ssp. madritensis), ripgut (B. diandrus), farmer’s foxtail (Hordeum murinum var. leporinum), Mediterranean barley (Hordeum marinum ssp. gussoneanum), and rattail (Vulpia myuros) along with brome fescue (V. bromoides). Within a few steps, the diminutive silver hair grass (Aira caryophyllea), dog’s tail grass (Cynosurus echinatus), and little quaking grass (Briza minor) appear. The latter’s larger relative rattlesnake grass (Briza maxima) is also common throughout the Preserve. Further along Road F south of the first serpentine, the widepread weed nit grass (Gastridium ventricosum) debuts. See the posting Replacement of the Native Vegetation and wild oat.

2006-04-04T08:23:00.000-07:00

spike bentgrass, Agrostis exarata, June-August, Native

Occasional in mesic areas such as Trail "a" near its intersection with Trail 1, Trail 2, and Mapache Trail, about 100 yards south of its intersection with Trail 10, near arroyo willow and sneezeweed (Helenium puberulum). Plants have a more or less dense inflorescence and awned lemmas; perennial without rhizomes or stolons. Illustration left from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

2006-04-04T08:22:00.000-07:00

Hall's bent grass, Agrostis hallii, June-July, native

The question of Agrostis hallii or A. pallens (the latter including A. diegoensis)

These rhizomatous, leafy grasses are usually easy to pick out in their in their vegetative states in appropriate habitat by their relatively long cauline leaf blades and short stem internodes. Determining species even when in bloom can be difficult because critical measurements of local material frequently overlap.

In The Jepson Manual 2 (adapted):
plants from rhizomes
4. Floret callus hairs 1.5–2 mm, gen > 1/2 lemma; ligule 4–7 mm ..... A. hallii (3)
4' Floret callus hairs gen minute, sparse, or 0; ligule gen < 3 mm .... A. pallens

rhizomes or stolons 0
31. Floret callus hairs 1.5–2 mm, gen slightly > 1/2 lemma; anthers >= 1.5 mm ..... A. hallii
31' Floret callus glabrous or hairs minute, << lemma; anthers gen < 1.5 mm .... A. pallens

Barbara Ertter writes in the Diablo Flora, 2nd ed (2002) about A. hallii:

The very similar A. pallens Trin. (= A. diegoensis Vasey) differs primarily in that the hairs at the base of the floret are lacking or nearly so, and florets and ligules are smaller in general. The placement of most specimens from the East Bay in A. hallii, including all those from Mt. Diablo, is based on previously existing identifications, even though they are not compatible with the key break given by Harvey (JepMan) (i.e., the hairs are mostly in the 0.5-1.5 mm range.) Harvey notes, however, that the geographic and ecological variation of A. pallens is in need of further study. (p. 348)

In the addenda (p. 404) a collection of A. pallens is cited (Ertter & Morosco 16433)

In the Marin Flora (Howell 1970), A. diegoensis is common and A. hallii uncommon, and Howell writes “this species [>A. diegoensis] and the preceeding [A. hallii] are nearly confluent and at times difficult to distinguish, although A. diegoensis is generally more delicate in foliage and inflorescence.” p. 82.

Howell’s leads:
h. spikelets 3.5-4.5 mm l.; lemma 3 mm. l; hairs at base of lemma more than
1 mm long .... A. hallii

hh. spikelets 2.5-3.5 mm l; lemma 2-2.5 mm l; hairs at base of lemma 1 mm
or less .... A. diegoensis

J. Thomas' leads in his Flora of the Santa Cruz Mountains:

spikelets 3.5-4.5 mm l; lemmas about 3 mm l; the hairs at the base 1 mm l or
longer; . . . hallii
spikelets usu less than 3.5 mm l; lemmas 2-2.5 mm l; the hairs less than 1
mm l; . . . diegoensis

A. hallii panicle illustration from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

A. diegoensis panicle illustration from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

CalPhotos images of Agrostis hallii herbarium vouchers by Steve Matson.
CalPhotos images of Agrostis pallens herbarium vouchers by Steve Matson.

2006-04-04T08:00:00.000-07:00

small-leaved bent grass, Agrostis microphylla, May–June, Native

One of four native annuals on our tour, occasional in serpentine, along the coast, and wet places where water has stood in spring. Walk out Trail 9 to the serpentine/chert contact where it grows with meadow barley, as well Road F just north of its intersection with Trail 9, on areas of especially thin serpentine soil, with other native annuals Vulpia microstachys and Deschampsia danthonioides. Look for the short grass with a dense, cylindrical flower head of single-flowered spikelets.
Illustration from Jepson Manual.
CalPhotos images of Agrostis microphylla herbarium vouchers by Steve Matson.

Name: Greek for pasture | small-leaved

2006-04-04T07:59:00.000-07:00

leafy bent grass, Agrostis pallens, June-August, Native

Brush-covered areas and along the margins of chaparral. CalPhotos images of Agrostis pallens by Steve Matson.

Agrostis hallii and A. pallens: These two rhizhomatous, leafy grasses in their vegetative states are usually easy to pick out in the appropriate habitat by their relatively long cauline leaf blades and short stem internodes. Determining species even when in bloom can be difficulty because critical measurements overlap. See Agrostis hallii entry.

A. diegoensis panicle illustration from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

CalPhotos images of Agrostis pallens herbarium vouchers by Steve Matson.

2006-04-04T07:50:00.000-07:00

wild oat, Avena fatua, February–June, Europe
slender wild oat, Avena barbata, February-June, Europe

Among the most abundant and widespread grasses that make California’s hills “golden,” wild oat (A. fatua) and slender wild oat (A. barbata) cover lowland California west of the Sierra and southern deserts. While not found in adobe bricks of some of the state’s oldest buildings, wild oat probably arrived soon after the time of European settlement of California in 1769. See the posting "Replacement of the Native Vegetation."

Cluster and Allard (1995) write:

Historical records indicate that Avena barbata was introduced to California from Spain (Robbins 1940) . The first introductions probably occurred during the Spanish-Mexican colonial period (1769-1846), but Avena barbata did not become a major component of the flora in all areas with Mediterranean-like climates until cereal agriculture spread throughout California in the mid-19th century.

Minnich (2008) considers Avena barbata a member of the late-19th century suite of invaders including farmers foxtail, ripgut brome and red brome. Though present earlier he argues that these second wave exotics began dominating California valley and foothill grasslands 1890-1920s, citing numerous cintemporaneous sources (Minnich, p. 186).

Burcham (1957) writes:

Accounts of travelers contain records of the widespread distribution of some of the most important introduced plants at a comparatively early period. Traversing a portion of the central San Joaquin Valley in 1833, Zenas Leonard remarked, "This day our course lay through a large prairie covered with wild oats—which at this season of the year when nothing but the stock remains, has much the appearance of common oats" (Leonard, 1934). There is a possibility that a person unfamiliar with the vegetation of California crossing this region in November when only stalks of the grasses remained—and this was the situation with Leonard—may have confused wild oats with needlegrass; but this possibility is hardly plausible in view of his later experience in the State. Leonard also described large areas covered with wild oats in the valley north of Mission San Juan Bautista and elsewhere in the Coast Ranges. During his visit to California in 1841, Wilkes (1845) noted about San Pablo Bay and the Carquinez Straits that "the hills are thickly covered with wild oats"; the country about San Francisco presented a rather singular appearance, he said, due to the color of wild oats when ripened. Bryant (1848) refers to the occurrence of wild oats many times in the account of his travels in California in 1846 and 1847; crossing the bottomlands of the Mokelumne River, along its lower reaches, he remarked: "We passed through large tracts of wild oats during the day; the stalks are generally from three to five feet in length." Bryant described the Santa Clara Valley between San Jose and San Francisco as "a flat plain . . . covered with a great variety of grasses, wild oats, and mustard. So rank is the growth of mustard in many places, that it is with difficulty that a horse can penetrate through it." In 1851 the party of Col. Eedick M'Kee found wild oats growing abundantly on the foothills from Santa Rosa northward into the Russian River Valley; they were not noted north of the divide between Russian and Eel Rivers by that party (Gibbs, 1860).

It is probable that Russian settlers at Fort Ross were first to introduce wild oats and mustard, and other plants, north of San Francisco Bay. During the period of their occupation of Fort Ross, Russian writers noted that mustard grew wild in many places, requiring no cultivation; in various years from 100 to 200 pounds of seed was gathered and sent to Sitka (Khlebnikof, 1835). "In 1833 wild oats made its appearance in many fields in such abundance as to smother the wheat and the only means to suppress it was to pasture cattle on the fields for several years ..." (Tikhmenef, 1861-63). Obviously seed of mustard and wild oats—as well as other alien plants—were introduced as impurities in crop plants, many of which had been obtained directly from the Spaniards (Essig, 1933). Infestations of the magnitude reported by these writers would indicate introductions within a short time after founding of the colony.

Avena fatua and A. barbata awns are attached on the back of its lemmas; with a hand lens observe that the awn is a continuation of the midnerve (vascular bundle), and that the lemma is nerveless above. The awn is an adaptation that assists seed dispersal. Purple needlegrass also has a conspicuous, self-drilling, moisture-driven, hygroscopic awn, as does the ubiquitous forb storksbill, whose drill is actually its long, sharply-pointed persistent style column attached to the ripe fruit.

Cultivated oat (A. sativa) is an occasional escape from birdseed, but doesn't persist. California wild oatgrass is a species of the genus Danthonia.

Name: Latin for oat | simple.

BURCHAM, LT. 1957. California Range Land: An Historico-Ecological Study of the Range Resource of California. Davis [Calif.]: University of California, 1957.
CLUSTER, PD; ALLARD, RW. Evolution of Ribosomal DNA (rDNA) Genetic Structure in Colonial Californian Populations of Avena barbata. " Genetics 139: 941-54.

MINNICH, RA. 2008. California's Fading Wildflowers: Lost Legacy and Biological Invasions. UC Press.

Illustrations of lemma tips of slender wild oat (attenuate to 4 mm l awns), below; and wild oat (short teeth), above

2006-04-04T07:46:00.000-07:00

purple false brome, Brachypodium distachyon, April-June, Europe

Widespread including serpentine, puple false brome, like Lolium, did particulary well in the long cool spring of 2006. Recognize it by the side-to-side compressed, overlapping spikelets, flat side toward the stem, spike-like inflorescence, and white stem nodes. It makes a strong showing just below the Field Station access road and toward the lake, near the goldenaster (Heterotheca sessiliflora ssp. echioides) site.

Purple false brome was first noted at JRBP in 1977. It is not included in John Thomas (1961) Flora of the Santa Cruz Mountains of California.

2006-04-04T07:45:00.000-07:00

rattlesnake grass, Briza maxima
little quaking grass, Briza minor

2006-04-04T07:40:00.000-07:00

California brome, Bromus carinatus var. carinatus, April–Oct, Native

California brome is a short-lived perennial, moderately tall to about 3 feet or more, and nodding. Side-to-side compressed florets open up (chevron pattern in illustration) as flowering progresses, a common grass transformation.

Frequently in partial shade, it also grows in full sun and in serpentine. Its leaves are slightly gray-green, mostly flat, and largely die-back in the summer. Leaf sheaths are either smooth or visibly soft-hairy. Florets disarticulate above the glumes, which are often seen on the old, standing culms.

Another tall perennial brome with strongly-keeled lemmas, B. catharticus, is a common campus weed has been found on the Preserve at the Dennis Martin site. It is distinguishable at arms-length by its very short awns (less than 3 mm) and smooth, dark-green stems. Another ruderal brome, B. stamineus, has been collected near the old lake bathhouse and the caretakers yard. It also has an open inflorescence, but unlike California brome and rescue brome, its branches are stiffly ascending. With a hand lens its broad (1 mm wide) transluscent lemma wings are apparent. It is said to accept summer water, remain green, and avoid summer dormancy.

Two varieties are recognized by FNA. Both have been vouchered for Jasper Ridge; var. marginatus is uncommon.

1. Most awns 8–17 mm long................................. var. carinatus

1. Most awns 4–7 mm long............................... var. marginatus

Name: ancient Gk name | keeled.

2006-04-04T07:35:00.000-07:00

ripgut grass, Bromus diandrus, April–July, Europe

Suprisingly, given their morphological differences, the annual ripgut can be mistaken at a distance for purple needle grass (Nassella pulchra). Take a second look. At a closer distance poverty brome might appear as depauperate ripgut.

Name: ancient Gk name | two-stamen.

Illustration from Leroy Abrams, Illustrated Flora of the Pacific States, Stanford University Press, 1923.

2006-04-04T07:30:00.000-07:00

soft chess, Bromus hordeaceus, March–July, Europe

Soft chess has naturalized in all continents except Antarctica, and is widely distributed in North America. It is most common in low-elevation valleys and foothills of California and southwestern Oregon where the climate is Mediterranean. Its spikelets are nearly circular in cross-section and are soft to the touch because of their hairs. It dominates or is co-dominate in numerous California annual grassland communities.

Species composition in California grassland is complex and varied, reflecting slight differences in climate, topography, and soil type—as well as gopher activity (tunnel digging), which is the subject of a long-term study by Richard Hobbs on serpentine at Jasper Ridge, where soft chess is established. Year to year compositional changes on the same site due to weather and gopher disturbance can be dramatic.

Name: ancient Gk name | Hordeum-like.

2006-04-04T07:15:00.000-07:00

woodland brome, Bromus laevipes, May–August, Native
narrow-flowered brome grass, B. vulgaris, May-July

Bromus laevipes has normally somewhat shorter flowering branches than California brome, borne on stems with shorter internodes, woodland brome (and its dried stalk too) has a crosier-like inflorescence, and usually offers a handshake. The lemma backs are rounded rather than keeled, and can be densely hairy--or not. Young spikelets are more or less cylindrical. Mature spikelets, however, are clearly laterally compressed. Woodland brome grows on serpentine and is widespread on the Preserve, usually in partial shade. It flowers later than California brome.

A form of woodland brome with glumes and lemmas evenly puberulent, mentioned in the Jepson Manual, has been called Bromus pseudolaevipes and is vouchered in the JRBP herbarium.

B. vulgaris looks very much like woodland brome but is typically taller with wider leaves and larger diameter stems, and grows in and around redwood groves on trails 1 and 2, where it is common.

Photographs of Bromus laevipes by Craig Cummings, June 26, 2006.

Name: ancient Gk name | polished.

2006-04-04T07:10:00.000-07:00

poverty brome, Bromus sterilis, April-June, Europe

Poverty brome can be confused for a small form of ripgut. Distinguising characteristics include the very long inflorescence branches relative to spikelet length, usually with one spikelet per branch. The spikelets are smaller than those of ripgut, the grass overall finer, and branches and spikelets less scabrous. The awn length can overlap the shortest range of ripgut lemma awns. At Jasper Ridge it is found in partial shade, is seldom dominant, and seldom is found in open grassland, where ripgut can dominate.

2006-04-04T07:00:00.000-07:00

Chilean brome, Bromus trinii (B. berteroanus in FNA, v.24:223-224)
Known from a serpentine outcrop in area H adjacent to the abandoned exclosure, until a second station was found March 4, 2007, several plants in bloom just a few yards east of the extensive Allium falcifolium area UTM 0568637, 4140177; Sector 24, upper 4B. In April 2010 it was found along trail 15 and also Rd F in serpentine. This pilose annual plant has a long awn (13+ mm) arising from the sinus of acuminate lemma teeth and the first glume has a single vein. Lemma backs are more or less rounded. The characteristic awn bend and twists is apparent in dried specimens.

2006-04-04T06:35:00.000-07:00

orchard grass, Dactylis glomerata, May-Aug

2006-04-04T06:30:00.000-07:00

California oatgrass, Danthonia californica, May–July, Native

California oatgrass is often cryptic, being low growing with flowering stalks that are typically horizontal near the ground, as if knocked down by a high wind. It forms some the most extensive stands of native grasses on the Preserve, including south of Trail 3 on either side of Rd. F, and in low-lying mesic areas north and south of Global Change site. At the latter site, which includes the vernal pond which provides habitat for California semaphore grass, California oatgrass forms conspicuous tussocks. It has self-fertile (cleistogamous) florets in lower stems stacked upon one another above the stem nodes.

Unlike most other native California grasses mentioned in this blog, which belong to the Pooideae subfamily comprised of mostly Northern Hemisphere, temperate region grasses, Danthonia belongs to the Arundineae Tribe of the Arundinoideae subfamily of Poaceae (subfamily Danthonioideae in the recent Flora of North America's treatment), and has a characteristic field character of that group, namely, ligules of hairs rather than a membrane. Other Arundinoid grasses seen locally include the serious wildland invasives giant reed and Pampas grass. Danthonia, with its long glumes and lemmas awned from the middle of the back, earlier was placed in the Avena Tribe. [The higher level classification of Danthonia has changed again in the Flora of North America.]

Name: for E. Danthoine of France | from California.

2006-04-04T06:25:00.001-07:00

slender hairgrass Deschampsia elongata, May-June

This delicate grass with a basal tuft of fine leaves might be confused with young Nassella lepida but seldom share the same habitat. Slender hairgrass is occasional in mesic areas such as trails 1, 2, 5, and 13, and abundant along the slope and in the swale on the west side of road D south of trail 6. On trail 5 look for it at the plank-buttressed section of trail below the old gate, growing with Collomia heterophylla, both blooming in May.

2006-04-04T06:25:00.000-07:00

annual hairgrass, Deschampsia danthonioides, May–June, Native

Look for its delicate, open panicle at the Trail 9 serpentine/chert contact, growing with meadow barley, small-leaved bent grass, and common hairyleaf fescue, and on Road F in small barren places north of the Trail 9 intersection with hairy fescue and hairyleaf fescue. It can be abundant on Road F at the well-known docent stop for the diminutive, fragrant Pogogyne serpylloides, where it is universally overlooked.

Name: J. L-Deslongchamps, France | danthonia-like.

Illustration, Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911
CalPhotos images of Deschampsia danthonioides.

2006-04-04T06:24:00.000-07:00

ehrharta, Ehrharta erecta, naturalized

Ehrharta erecta has only recently been noticed on the Preserve. In early December, 2005, at Bear Creek and Sand Hill Rd fence, the herbarium crew collected ten or more ehrharta, fruiting. Appearing at first blush like an onion-grass, the small-flowered melic Melica imperfecta, it was dispensing its fertile florets far and wide among the tall cyperus and California blackberry. It can now be found along San Francisquito Creek in the Preserve, and is well-established around the Indian grinding rock at the beginning of Trail A.

Native to the Western Cape, it is one of a formidable South African contingent including Cape ivy, and yellow oxalis (Bermuda buttercup) that are colonizing, inexorably, significant portions of coastal California. (Bossard 2000; Sigg 2003). It is a challenge to walk anywhere in San Francisco or Berkeley and not find ehrharta. It was not listed in the 1958 A Flora of San Francisco, (The Wasmann Journal of Biology 16: 1-157) nor in John Thomas (1961) Flora of the Santa Cruz Mountains of California: a Manual of the Vascular Plants. It has colonized Stanford's prime garden areas including the Inner Quad circles, and can be found in the California Native Garden. Ehrharta propagates by seed and exhibits both upright and trailing growth habits. It is a member of a small old world grass tribe of perennials and annuals that has been classed differently by authorities into higher taxa/subfamilies (Gould 1983), and is currently classified in subfamily Ehrhartoideae, which also includes the California native Leersia oryzoides.

A.S. Hitchcock And A. Chase wrote of ehrharta in the 1950 Manual of Grasses of the United States:

Escaped, Berkeley, CA (evidently from the campus of the University of California). Shows considerable competitive ability and may become of value in replacing some of the troublesome weeds.

Philip Munz noted in his 1959 A California Flora, "Naturalized on the Berkeley campus. . . Introduced from South Africa." Sigg (2003) says that it was collected by G. Ledyard Stebbins as "adventive [introduced but not yet naturalized] in Botanical Garden, UCLA Campus, Los Angeles, in May 1946," and asks whether this collection was the source of Stebbin's research material? Stebbins, an eminent plant geneticist and founding member of the California Native Plant Society, had earlier written that ehrharta "became established as an adventive in northern California about 1930." (Stebbins 1985). Dr. Stebbins wrote in The ladyslipper and I (p. 83) that before he experimented with ehrharta that it was "already spontaneous in a small corner of the Berkeley campus".

Dr. Stebbins introduced ehrharta into test plots in the San Francisco Bay region in 1943 as part of an experiment:

. . . 22 different plantings were made of diploid and autotetraploid [created by Stebbins in his lab] Ehrharta, some of which consisted of seed sown in 5 x 5 m plots . . . while others were started by planting well-rooted clonal divisions . . . Sixteen of the plots were on the campus of the University of California, Berkeley, and two each in the inner Coast Ranges of Napa County, the campus of the University of California at Santa Cruz, and the town of Carmel. (Stebbins 1985).

He noted in the 1985 article "Polyploidy, Hybridization, and the Invasion of New Habitats" that the unaltered specimens were reseeding in most of the plots, and had spread extensively into surrounding areas. Of a Strawberry Canyon plot:

For several years . . . little change was noticed, but about 1965 ehrharta spread extensively westward. The plants colonized relatively diverse areas, some of them in hard-packed soil and others in well-drained areas under redwoods.

Dr. Stebbins wrote about the experiment in his memoir:

Of the 10 sites in which I had planted seeds, only three gave results after the first generation, and in only one of them was the autopolyploid at first superior to the diploid planted next to it. Between the 10th and 15th generation , even this superiority disappeared, and in 1970, 26 years the original planting, the diploid spread first over a few meters and later over 100 meters beyong the original planting while the autotetraploid was almost completely confined to the original area. The superiority of the diploid over the auto tetraploid increased until 1984, 40 years after the original planting.

Time will tell how persistent and extensive ehrharta will become at Jasper Ridge.

image source: California Invasive Plant Council: Invasive Plant Inventory

References (* = in JRBP library)

Bossard, Carla. 2000. Invasive Plants of California's Wildlands.* http://groups.ucanr.org/ceppc/Invasive_Plants_of_California's_Wildlands/
Gould, Frank and Robert Shaw. 1983. Grass Systematics. 2^nd ed.*
Hitchcock, A.S. 1950. Manual of Grasses of the United States.*
Jepson Online Interchange. http://ucjeps.berkeley.edu/interchange.html
Munz, Philip. 1959. A California Flora.*
Sigg, Jacob. 2003. "Triple Threat from South Africa." Fremontia 31(4):21-28.
Stebbins, G.L. 2007. Ladyslipper and I. Missouri Botanical Garden.
Stebbins, G.L. 1985. "Polyploidy, Hybridization, and the Invasion of New Habitats." Ann. Missouri Bot. Gard. 72:824-82. In JSTOR from Stanford IP addresses: http://links.jstor.org/sici?sici=0026-6493%281985%2972%3A4%3C824%3APHATIO%3E2.0.CO%3B2-5

2006-04-04T06:15:00.000-07:00

blue wildrye, Elymus glaucus, April–June, Native

Blue wildrye grows aggressively in full sun and canopy openings and in dry to moist soil, and is one of the most common grasses of the West. It grows in grassland, chaparral, woodland, and forest, and is associated on the Preserve with Bromus carinatus. Its grains (seeds) were collected for food; burned grass seeds are conspicuous food remains recovered at local Indian sites.

A short-lived bunchgrass, it can also spread by short stolons, vegetative reproduction being a notable feature of many grasses. The eminent grass specialist Agnes Chase writes, “This ability to make new shoots and cover large areas . . . is an adaptation that allows grasses to dominate open habitats, coexist with grazing animals, and survive fires.” Rhizomes and stolons are specialized stem branches that form at basal stem nodes and grow horizontally. Stem growth resulting in bunch grasses primarily grows up inside the sheath and emerges at its apex.

The inflorescence is a true spike, its individual spikelets, usually in groups of 2, directly attached to nodes of the flowering stalks without pedicels (sessile). Infl. 6 to 16 cm long, not breaking apart with age (look for the old flower stalks); lemma awns 1-3 cm. long. Leaves flat, upper leaf often flag-like (folded at 90º angle to stalk).

Subspecies virescens which has shorter lemma awns, < 5 mm long, has also been reported, but not vouchered, for the Preserve. This grass quite possibly has a sporadic distribution on serpentine but has been overlooked in the field.

Name: ancient Gk name for millet | with a whitish coating.

2006-04-04T06:13:00.000-07:00

Elymus glaucus x E. multisetus, squirreltail hybrid, May-August (Elymus hanseni; Sitanion hanseni)

There are several example on and off serpentine. The plants most easy to view is growing just off Trail 9, about 100 yards from Road E, on the north side of Trail b about 50 yards from Road F, and at the beginning of Trail 8 near its intersection with Road D. Elymus glaucus and E. multisetus grow nearby in both locations. This grass was shown by G. L. Stebbins to be a F1 sterile hybrid between Elymus glaucus and, in this case, E. multisetus.

2006-04-04T06:11:00.000-07:00

big squirreltail, Elymus multisetus, April–August, Native

A coarse grass like Elymus glaucus, it has the endearing quality of easy recognizability and a memorable common name. It was formerly known as Sitanion jubàtum. Lemma awns (located between 2-lobed tips) are 2.5 to 10 cm. long. Illus.: suppl. photocopies.

Name: ancient Gk name for millet | multi-bristled, referring to the awn-like glumes.

2006-04-04T06:00:00.000-07:00

California fescue, Festuca californica, March-July, Native

© Illustration courtesy of Good Nature Publishing. Beautiful California native grass color poster available from www.goodnaturepublishing.com

This most beautifully proportioned grass is frequently found in partial shade on north-facing slopes, in open forest, and chaparral. It tolerates serpentine as demonstrated by the large tufts below Trail 15. The largest stand is on both sides of Trail 4, occasional elsewhere. Flowering stems rise to 6 ft, inflorescence branches open. Our examples have bluegray, narrow, 4-mm-wide leaves, the margines inrolled. Other forms have green foliage and/or flat leaves. Look for the hairy sheath collars. Its native range is from Monterey to Oregon generally below 6,000 feet. A disjunct population in the San Bernadino Mtns. has been called var. parishii. San Francisco is the type locality.

Name: ancient name | from California.

California distribution (Beetle, 1947)

2006-04-04T05:59:00.000-07:00

Elmer's fescue, Festuca elmeri, May-June, Native

Only known from several locations in oak-madrone woodland under a full canopy on the footpath (bird trail) before Trail 7 splits off of Trail 6 near its intersection with Road F, and along Trail 7 where the largest patch is a few hundred yards south of Hillside Lab. In bloom May 9, 2007. Elmer's fescue might also be found in similar wooded habitat on NE facing exposures.

California distribution (Beetle, 1947)

2006-04-04T05:50:00.000-07:00

meadow barley, Hordeum brachyantherum, April–June, Native

A trim, tufted native perennial on Trail 15 in the swale at the serpentine contact 65 yards south of Vestal’s exclosure, Trail 9 at the serpentine/chert contact, and elsewhere along Road F north of the Trail 9 intersection, and other shallow drainages, especially on serpentine. The old Hordeae (barley) tribe was characterized by sessile spikelets on opposite sides of the rachis. This small, temperate region tribe has included some of the world’s most important cereals: wheat, barley, and rye. It also includes our native Elymus species.

Name: barley | short anthers.

Photo right by Toni Corelli, 7/19/06. Hordeum brachyantherum on Trail 15. Elymus multisetus is in the foreground right.

2006-04-04T05:40:00.000-07:00

junegrass, Koeleria macrantha, April–July, Native

A handsome, long-blooming bunchgrass, look for junegrass on serpentine. Off serpentine, at arm’s length, it can be confused with orchard grass, Dactylis glomerata, which has distinctive stiff, comb-like hairs on the lemma margins, cauline leaves, and a smooth rachis (axis of the inflorescence). Junegrass has tiny hairs on the rachis; use your hand lens. The spike-like junegrass puffs up when in full flower and contracts after pollination.

Name: for G.L. Koeler, b. 1765 | large anthers.

2006-04-04T05:39:00.001-07:00

alkali rye grass, Leymus triticoides, May-July, Native

Recognizable by it bluish-green color, narrow (about 4 mm wide) leaves, spike-like inflorescence without noticeable lemma awns (at arm's-length), and spreading habit. The glumes are awl-like without visible veins. There are normally two spikelets per node. Alkali rye grass is widespread in the academic preserve along roads where ditches collect water, in swales, and drainages (large stand just south and east of the Dish in a low area where paths form a V), and in seasonally wet areas along the Stanford Ave. Greenbelt trail toward its west end. Holstein (2001) "Pre-agricultural Grassland in Central California", Madrono 48: 253-64) argues that the turf-forming alkali rye grass, and not purple needle grass, was a dominate grass of the Central Valley prior to development.

On Jasper Ridge Biological Preserve it grows not far from the main entrance gate on Sand Hilll Road and on both sides of the Bear Creek Road near the Verbena lasiostachys var. scabrida site. Is also found with Elymus glaucus near the intersection of lake and lakeside lab road, near the bath house site. Alkali rye grass is frequently green while other herbaceous plants are dried out.

Photo right by Toni Corelli, 6/30/2006.

2006-04-04T05:39:00.000-07:00

Italian ryegrass, Lolium multiflorum, April–Oct
perennial ryegrass, Lolium perenne

Lolium spikelets are arranged edgewise to the rachis (axis), and the first or inner
glume is suppressed except in the terminal spikelet. A branched form, a hybrid, can also be found on the Preserve. John Thomas in his Flora of the Santa Cruz Mountains writes that branched Lolium has been called "L. multiflorum var. ramosum Guss. ex Arcang" (p. 89 ). In the Manual of Grasses of North America branched lolium is included in a complex of grasses called Lolium x hybridum:

Lolium used to be included in the Triticeae [as in John Thomas], but evidence from genetics, morphology, and other studies show a close relationship to three former Festuca species included here in Schedonorus. Artificial hybrids have been produced among L. perenne, L. multiflorum, Schedonorus pratensis, and S. arundinaceus.

The Flora of North America treatment for L. multiflorum and L. perenne:

2 Plants long-lived perennials, with 2-10 florets per spikelet; lemmas unawned or with awns to 8 mm long ..... L. perenne
2' Plants annuals to short-lived perennials, with 10-22 florets per spikelet; lemmas with awns to 15 mm long, rarely unawned ..... L. multiflorum

Lolium perenne and L. multiflorum are interfertile and intergrade. Typical L. perenne differs from L. multiflorum in being a shorter, long-lived perennial with narrower leaves that are folded (rather than rolled) in the bud.

JRBP’s some 60 acres of serpentine soils is a small portion of the 3000+ acres exposed in the Bay Area (McCarten, 1993). It is a beautiful landscape of native prairie grading variously into serpentine chaparral, woodland, and oak savanna. There are no known, federal or state listed rare plants or animals associated with the Jasper Ridge serpentine, though there are some uncommon plants such as Allium peninsulare francsicanum (McNeal, 1977; 1992) and Lessingia hololeuca. The onion and the wooly-headed lessingia can be seen near the beginning of trail 5, the Lost Serpentine loop. The remaining bay checkerspot butterfly population appears to have been extinct at JRBP as of 1999 (Weiss, 1999).

The ridgetop has also not been grazed since 1960. Grazing removal has been detrimental to the native plant diversity of other sites (Weiss, 1999; Edwards, 1992, 1995; xxxx) Prevailing NW winds have resulted in less Nitrogen deposition from air pollution at JRBP than at some other Bay Area sites (Weiss, 1999). Increased N favors annual grasses by mitigating some of the harsh chemistry for plants of serpentine soils. JRBP serpentine soils had not been heavily invaded by Bromus hordeaceus, Lolium, or Avena by the early 1990s (Hobbs & Mooney, 1995). An increase of Italian ryegrass in 1998 corresponded with record El Niño rainfall (Weiss, 1999). Lolium multiflorum appears in all JRBP floras. The earliest record for Lolium growing in the serpentine is from Herb Dengler’s 1962/63 fieldnotes recently transcribed by Zoe Chandik. On May 19, 1962 he writes, evidently with reference to both Bromus hordeaceus and Lolium, “Mediterranian grass has successfully invaded the serp this year.” Springer (1938) found Italian rye grass to be “frequent along roadsides and in open fields and on openly wooded slopes near roads.” Thomas (1961) did not report Italian rye grass growing on serpentine in the Santa Cruz Mountains. McNaughton (1968) did not report Italian rye grass on serpentine. In 1990 the third revised edition of the Jasper Ridge Docent Handbook still identified only soft chess from among the Preserve’s naturalized grasses growing on serpentine. Armstrong and Huenneke (1993) documented Lolium was common in serpentine by 1985-86 and that it was negatively effected by drought. In 2001 and 2002 Lolium accounted for 32% and 20%, respectively, cover of Stuart Weiss’ JRBP serpentine transects (Weiss, 2002). In Spring 2006 the herbarium crew assisted in two relevant-to-this-issue surveys, a repeat of the Armstrong and Huenneke transect; and the vegetation component of a small mammal inventory. It is our impression that Lolium may approach a frequency of 80% to 90% in these serpentine quadrats. Hobbs et al. (2007, p.554-45) data shows lower coverage and frequency of Lolium for 1983-2003. The herbarium crew has not examined Hobbs' 50 x 50 m quadrats. Also see CNPS Vegetation Rapid Assessment Field Form JASP0001 3/25/2008.

Weiss writes:

The invasive grasses that have dramatically changed California’s grasslands are poised to dominate the last refugia for the native grassland flora and fauna, given the chance. That chance is provided by smog-induced fertilization, but only with the additional land-use change of removing grazing . . . It is ironic that grazing, which has contributed so greatly to the transformation of California’s native grasslands, may prove necessary for their maintenance . . .

—Weiss, 1999, p. 1485

Exhaust from cars, about 110,000 vehicles a day on Highway 101, along with other urban sources, annually deposit 15 to 20 pounds of nitrogen per acre on Coyote Ridge south and east of JRBP, according to Weiss's monitoring equipment.

Some of the nitrogen is absorbed by living plants, while small particles of the pollutant stick to plants and the ground and are washed into the soil by rain. By contrast, pollution from power plants and vehicles each year deposits just four to five pounds of nitrogen per acre on Jasper Ridge, a Stanford University biological reserve half an hour away. http://www.washingtonpost.com/wp-dyn/content/article/2006/05/21/AR2006052100725.html

However, even as smog-derived Nitrogen deposition is not as great at JRBP (upwind from most pollution sources) as it is for other serpentine grasslands that are downwind, the spread of Lolium shows other factors can and will contribute to annual grass invasions, and that once introduced, some naturalized plants will have the genetic adaptability to persist on serpentine and other nutrient-poor soils.

Name: Latin name for ryegrass | multi-flowered.

2006-04-04T05:30:00.000-07:00

Three melics compared: Melica torreyana (left); M. imperfecta with relaxed panicle branches (center) ; and M. californica (right). Ruler in cm. Scan of grass specimens.

California melic, Melica californica, March−June, Native

California melic is a larger, taller grass than small-flowered melic and Torrey’s melic, its branches generally erect and appressed, but no less beautiful, with a narrow yet graceful inflorescence and bright green tuft of narrow, flat leaves. It has the brightest green foliage of the native perennials on our tour. The entire plant is glorius in full sun, and is frequently near rock outcrops. It can be seen off serpentine in the vicinity of the intersection of trails 12 and 10. See the entry for M. torreyana for additional habitat notes. California melic usually has corms (expanded stem base), which is characteristic of some species of the Melic or Onion grass genus.

Name: Latin for honey, or old Italian name for a plant with sweet sap | from California.

Illustration from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

small-flowered melic, Melica imperfecta, Mar–June, Native

Mature specimens usually exhibit spreading panicle branches, while the inflorescence of M. torreyana is usually narrow, branches upright, appressed. Use this feature as a field characteristic to distinguish these otherwise similar grasses that sometimes grow companionably together. See small-flowered melic on Grassland Fire Road west of the Trail 15 intersection, and throughout the Preserve on steep, mesic slopes. It has not yet been found on serpentine at Jasper Ridge.

Name: imperfect

Torrey’s melic, Melica torreyana, March−June, Native

Growing to 2 feet tall, Torrey’s melic is smaller and finer than M. californica. Similar to the two Nassellas, the more delicate-featured melic prefers partial shade in woodland or the edge of grassland and chaparral, while M. californica is often seen on exposed, rocky slopes, though it will tolerate some shade. Torrey’s is strikingly handsome in diffuse light, which plays on its transluscent, papery glumes and red-backed lemmas, creating the appearance of a necklace of rice-like, light and dark beads. It's narrow, flat, shiny-green leaves can form dense tufts.

Name: John Torrey (1796-1873), American botanist.

California distribution (Beetle, 1947)

2006-04-04T05:29:00.000-07:00

Alaska oniongrass, Melica subulata, May−June, Native

This grass could be mistaken for either California brome or particularly Bromus vulgaris, which also grow along trails 1 and 2. It would not be confused, however, for either Torrey's or small-flowered melic which also grow along these trails. Unlike the bromes, its leaves, sheath, and stems are shinny/glabrous rather than dull green/hairy. Like bromes, melics have closed sheaths. It also lacks the awned lemmas of the two bromes, thought its lemmas are conspicuously acuminate (subulate). It is abundant in section 14, grids 3D, 3E, in the vicinity of 568460, 4140723. Grows with Holodiscus discolor, Aesculus californicus, yerba buena, Trillium chloropetalum, Tellima grandiflora, Rubus ursinus.

Geyer's melic (Melica geyeri) has been reported from above Trail 1 in the vicinity of the Tafoni caves, but the report rested on a misidentified voucher. The nearest known location of Geyer's melic is about 900 feet higher than Jasper Ridge in the Santa Cruz Mountains in the nearby Los Trancos Open Space Preserve and along the Los Trancos Creek Trail in Palo Alto's Foothill Park. These two melics at arms length look similar. Geyer's melic has glabrous lemma's with acute tips; Alaskan melic has hairs on the lemma veins and the lemmas are acuminate, i.e., long tapering.

2006-04-04T05:20:00.000-07:00

purple needlegrass, Nassella pulchra, Mar–June, Native

In 2004, purple needlegrass became the official California state grass. Sen. Michael Machado, D-Linden, introduced the successful bill that gave the perennial bunchgrass Nassella pulchra (Stipa p.) a place alongside serpentine, California poppy, and grizzly bears as symbols of the Golden State. He had pointed out that Utah and Nevada have similarly honored Indian rice grass (Achnatherum hymenoides), and Montana recognizes blue bunch wheat grass as its state grass. “Purple needlegrass can become a signature species,” he told an interviewer. “Part of appreciating who we are is understanding the history of what was. Purple needlegrass thrived in California soil long before Europeans arrived here. Native Californians ate the seeds. During the Mexican era, ranchers moved their cattle through vast sections of Nassella and other perennial grasses.”

Purple needlegrass can compete in non-serpentine soils with annual grasses; see it, for example, here and there along the Dish Trail on the Academic Preserve. Its presence along the path from the overflow lot to the Field Station and in the picnic area results from staff seeding the area in 2002 with locally-collected seed.

Purple needlegrass forms tufts, creating a hummocky appearance on the landscape. This is nicely seen (depending on the mowing schedule) at the fire-truck turn around on chert-derived soils where Grassland Fire Road meets Goya trail. Older plants generally have larger tufts. Research at the Hastings Natural History Reservation in Carmel Valley indicates that larger individuals, up to 12-inch diameter, are 100-200 years old, or perhaps substantially older.

Purple needlegrass has been the subject of much discussion and debate. Did it dominate pre-European settlement grasslands? Its response to fire and grazing? The significance of ecotypic species variation for revegetation uses? Its suitability for restoration in different soils and climates. N. pulchra is probably the most common native perennial grass today, and in many locations that is due in some part to human agency: it colonizes disturbed areas and is widely used in revegetation. Nassella pulchra and Nassella lepida are common on the Preserve. Though these two needlegrasses are reported to hybridize, we have not noticed intermediate forms at Jasper Ridge.

foothill needlegrass, Nassella lepida, Mar–June, Native

Foothill needlegrass thrives in shady margins of chaparral and woodland, but also grows in full sun, often in company of the locally more abundant N. pulchra. Spikelets are single-flowered, as are those of all other members of Stipeae (needlegrass tribe). The two Preserve needlegrasses resemble one another but N. lepida is smaller and noticeably finer, with lemma awns usually about half-as-long (to 3 cm.) as those of N. pulchra.

Look for it in serpentine along the edge of the diminutive forest bordering Trail 15, growing with another partial-shade-loving grass, Melica torreyana. Every so often N. lepida and N. pulchra are together under the canopy of Rhamnus californica, Quercus agrifolia, and Q. durata. Foothill needlegrass, like its frequent companion Melica torreyana, grows on a variety of soil-types on the Preserve.

Nassella pulchra and Nassella lepida are common on the Preserve. Though these two needlegrasses are reported to hybridize, we have not noticed intermediate forms at Jasper Ridge.

Name: Latin: nassa, a basket with a narrow neck | elegant.

Illustration from Leroy Abrams, Illustrated Flora of the Pacific States (Stanford University Press, 1923)

2006-04-02T08:51:00.000-07:00

California canary grass, Phalaris californica

The largest population grows in a seep several hundred yards south of Trail 3 on the northeast side of the ridge near the sandstone/serpentine contact (Area C). Beautiful purple-tinted flower heads bloom May-June among a great swath (for Jasper Ridge) of Carex serratodens and Stachys pychnantha.

2006-03-31T21:30:00.000-08:00

semaphore grass, Pleuropogon californicus
May-June, Native annual

The more common of the three semaphore grasses in California, it extends inland to the foothills of the Cascades and Sierra Nevada. Growing in a vernal pond near Sand Hill Road, this location is an excellent example how special habitats provide refuge for native plants. California semaphore grass, California oat grass (Danthonia californica), and California meadow barley (Hordeum brachyantherum) grow in and around the pond stratified by tolerance for standing water. All are normally in bloom by early May. Juncus phaeocephalus and Carex subbracteata are also present. California oat grass occupies the outer drier area around the depression and grades rather sharply to annual grassland dominated by Avena barbata and Bromus hordeaceus, though Nassella pulchra is sometimes a conspicuous member of the drier habitat.

2006-03-31T09:29:00.000-08:00

one-sided bluegrass, Poa secunda ssp. secunda, Feb–May, Native

Poa is the largest genus (ca. 500 species) of the grass family Poaceae (ca. 10,000 species worldwide), the fourth largest flowering plant family after Orchids, Asters, and Legumes. Represented by 91 taxa (species, subspecies, and varieties) at Jasper Ridge, Poaceae is the second largest family on the Preserve; Asteraceae is the largest.

Poa secunda is highly variable and grows in many vegetation types from sea level to 12,500 feet, near the top of Sierra Nevada peaks. Our form was formerly called Poa scrabella. In a cool, wet spring such as 2005 (March to early April), it can be abundant on serpentine, where it is particularly beautiful, leaves and stems having a blueish cast. Lemma tips are typically purplish. When flowering, called anthesis, stamens become exserted, dangling from their florets in the breeze, imparting an open hoary appearance to the plants. Leaves are not abundant and die back soon after flowering, at least in lowland grasslands. Exsertion of staminate and pistillate parts on the path to disarticulation and seed dispersal occurs in many but not all grasses, and contribute to the changing appearance of grasses through their developmental cycle. These transformations can confuse the observer. Poa secunda has an early, tightly-appressed, upright inflorescence whose branches may relax, often becoming open and airy, during full bloom in March. Plants typically metamorphose as the stamens wither, turning brownish-tan causing the inflorescence to appear shaggy. The stamens soon fall off. Some inflorescences persist as a tight flowering head of glumes and a few florets (as shown in the illustration).

The ubiquitous Poa annua is also present on the Preserve in roads, including those through serpentine, and other disturbed areas.

Name: ancient Gk name | turned to one side (which is not obvious).

Illustration from Intermountain Flora

2006-03-31T09:28:00.000-08:00

Scribneria bolanderi, March-May, Native annual

There is a voucher (498082) by John Thomas, collected 15 May 1963, generally in the area these photos were taken (In Road F, northern end of Serpentine Prairie.

The longest culms in the photographs are about 1 inch. Photos by Judy Mason on March 23, 2007 on Road F (UTM 568511/4140158), just north of the oak island. A number of individuals growing with flowering Juncus bufonius and young Calycadenia multiglandulosa. Other plants have been found in the same general area in the bare zones in the margins of the serpentine prairie traversed by Road F, and growing in openings of the serpentine chaparral adjacent and west.

2006-03-31T09:27:00.000-08:00

tall trisetum, Trisetum canescens, May–Aug, Native

In the woods at the Escobar Gate end of Trail 15 south of the first meadow, and in shady margins north of the exclosure, Road E south of Trail 7, 50 yards south of Hillside Lab on Trail 7 growing with the Erigeron foliosus, and the small meadow uphill near the end of Trail 2. A grass of open woodland and woodland margins, it is occasional and widely spread, usually only a few plants together. Inflorescence is similar in appearance to Deschampsia elongata.

Photo right by Toni Corelli, May 10, 2006.

Name: three bristle | with short white hairs.

2006-03-31T09:04:00.000-08:00

Vulpia bromoides and V. myuros, comparison of glumes

V. myuros: Lower glumes less than 1/2 the length of the upper glumes (lower glumes 0.5-2 mm, 1/5-1/2 the length of the upper glumes; upper glumes 2.5-5.5 mm). Illustration of spikelet from Manual of the Grasses of the United States, 2 ed. PDF: http://standish.stanford.edu/bin/object?00003911

N.B. Both var. myurus and var hirsuta (Festuca megalura) are present.

V. bromoides: Lower glumes 1/2 or more the length of the upper glumes (Lower glumes 3.5-5 mm, 1/2-4/5 the length of the upper glumes; upper glumes 4.5-9.5 mm).

—Manual of Grasses of North America http://herbarium.usu.edu/grassmanual/

Also see comments for V. microstachys

2006-03-30T21:00:00.000-08:00

hairyleaf fescue & hairy fescue, Vulpia microstachys var. pauciflora & V. m. var. ciliata, April–May, Native

These annuals can form locally open, airy forests to about 25 cm tall, on serpentine and other thin soils. They have a less-threatening aspect than most of their naturalized relatives, whose inflorescences usually appear congested, lemmas bristling with awns. One of those related taxa, Vulpia myuros var. hirsuta (formerly V. megalura), which also grows on the Preserve, was first recognized only a few decades ago as not native, as it was earlier believed. (R.I. Lonard and F.W. Gould. “The North American Species of Vulpia,” 22 Madroño, 1974: 217-230.) As a result, some researchers proposed that annual forbs filled the interstitial spaces of perennial grasslands (as we see today on the Preserve’s serpentine), because there seem few other common native annual grass candidates.

The varieties of V. microtachys have an enlargement in the inflorescence branch axils that cause the branches to reflex in flower. Observing these pulvini, often reddish, requires a hand lens for most people. A more easily observable field character of V. microtachys is the angle formed between the lowest inflorescence branch relative to the upper branches: when viewed from above this feature is striking, the planes formed by the branches are 90+ degrees.

Photo right by Toni Corelli, May 14, 2006. Vulpia microstachys var. pauciflora center and right. Bromus madritensis var. madritensis is lower left in photo.

Name: For J.S. Vulpius, German botanist | small spike-like | few-flowered.