Nassella trichotoma |
Nassella lepida |
|
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serrated tussock, serrated tussockgrass, yass tussockgrass |
foothill needlegrass, foothills nassella, foothills needlegrass, small-flower stipa, smallflower tussockgrass |
|
Habit | Plants perennial; cespitose, not rhizomatous. | Plants perennial; cespitose, not rhizomatous. |
Culms | 20-60 cm tall, about 1 mm thick, erect, internodes glabrous; nodes 2-4, pubescent. |
35-100 cm tall, 0.7-1.2 mm thick, erect, bases sometimes decumbent, internodes glabrous, or the lower internodes pubescent just below the nodes or throughout, varying within a plant; nodes 3-4, pubescent. |
Sheaths | glabrous, smooth; collars glabrous, without tufts of hair at the sides; ligules 0.5-2.5 mm, glabrous, obtuse; blades 15-45 cm long, 0.2-0.6 mm wide, convolute, stiff, scabridulous. |
glabrous or coarsely hairy, sometimes scabridulous, margins glabrous; collars hairy, particularly towards the sides, hairs at the sides 0.2-0.5 mm; ligules 0.1-0.6 mm, glabrous, truncate to rounded; blades 12-23 cm long, 1-3.5 mm wide, flat to convolute, lax, abaxial surfaces scabridulous, adaxial surfaces coarsely hairy. |
Panicles | 8-25 cm, open, lax, sparse; branches 2-6 cm, with 1-8 spikelets; pedicels 3-12 mm. |
9-55 cm, open; branches 1-8 cm, ascending to spreading, with 1-6 spikelets; pedicels 1-5 mm. |
Glumes | subequal, 4-10 mm long, 0.9-1.2 mm wide, narrowly lanceolate, scabridulous, apices aristate; florets 1.5-2.5 mm long, 0.7-0.9 mm wide, terete, widest near the top; calluses 0.1-0.3 mm, acute, strigose, hairs reaching to midlength on the lemmas; lemmas strongly tuberculate, particularly distally, mostly glabrous, narrowing abruptly to the crown, midveins pubescent proximally; crowns about 0.5 mm long, about 0.2 mm wide, straight-sided, rims entire or irregularly lacerate, glabrous; awns 15-35 mm, eccentric, straight to twice-geniculate; anthers 3, 1-1.5 mm. |
subequal, 5.5-15 mm long, 0.5-1 mm wide, narrowly lanceolate, glabrous, acuminate; florets 4-7 mm long, 0.5-0.7 mm wide, terete, widest near or slightly above midlength; calluses 0.4-1.6 mm, sharp, strigose; lemmas papillose, initially evenly pubescent, becoming glabrous between the veins at maturity, tapering to the crown; crowns 0.25-0.3 mm long, 0.15-0.2 mm wide, straight-sided, rims with 0.3-0.6 mm hairs; awns 12-55 mm long, 0.1-0.15 mm thick at the base, first geniculation distinct, second geniculation obscure, terminal segment cernuous; anthers 3, 2-2.5 mm, penicillate. |
Caryopses | about 1.2 mm, oblong, dark brown. |
3-4 mm. |
2n | = 36. |
= 34. |
Nassella trichotoma |
Nassella lepida |
|
Distribution |
IL; KY; NC; SC |
CA
|
Discussion | Nassella trichotoma is a native of South America, and has been accidentally introduced into the United States. Because it is on the U.S. Department of Agriculture's noxious weed list, all known populations have been eliminated. New populations should be reported to the Department. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Nassella lepida usually grows on dry hillsides in chaparral habitats, from California into northern Mexico. It is most likely to be confused with N. cernua, but differs from that species in its shorter, thinner awns and more numerous spikelets. It occasionally hybridizes with N. pulchra. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 177. | FNA vol. 24, p. 174. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Stipa lepida var. andersonii, Stipa lepida | |
Name authority | (Nees) Hack, ex Arechav. | (Hitchc.) Barkworth |
Web links |