Nassella trichotoma
serrated tussock, serrated tussockgrass, yass tussockgrass
20-60 cm tall, about 1 mm thick, erect, internodes glabrous;
nodes 2-4, pubescent.
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.
8-25 cm, open, lax, sparse;
branches 2-6 cm, with 1-8 spikelets;
pedicels 3-12 mm.
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.
about 1.2 mm, oblong, dark brown.
= 36.
Nassella trichotoma
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.)
IL Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
