Nassella trichotoma

(Nees) Hack, ex Arechav.
Common names: Serrated tussockgrass Yass tussockgrass
Treatment appears in FNA Volume 24. Treatment on page 177.

Plants perennial; cespitose, not rhizomatous. Culms 20-60 cm tall, about 1 mm thick, erect, internodes glabrous; nodes 2-4, 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. Panicles 8-25 cm, open, lax, sparse; branches 2-6 cm, with 1-8 spikelets; pedicels 3-12 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. Caryopses about 1.2 mm, oblong, dark-brown. 2n = 36.

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Nassella trichotoma"
membranous +  and scarious +
penicillate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
awned +, bifid +, bilobed +  and entire +
aristate +
Mary E. Barkworth +
(Nees) Hack, ex Arechav. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
straight +
eccentric +
2 times-geniculate +
1.5 cm15 mm <br />0.015 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
keeled +  and rounded +
pale color +
intravaginal +, extravaginal +, branching +  and basal +
constricted +
15 cm150 mm <br />0.15 m <br /> (45 cm450 mm <br />0.45 m <br />) +
not evident +
scabridulous +
cross +, linear +  and narrowly lanceolate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
spikelike +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
well-developed +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
Serrated tussockgrass +  and Yass tussockgrass +
straight-sided +
perennial +  and annual +
20 cm200 mm <br />0.2 m <br /> (60 cm600 mm <br />0.6 m <br />) +
10 cm100 mm <br />0.1 m <br /> (175 cm1,750 mm <br />1.75 m <br />) +
not woody +
1 cm10 mm <br />0.01 m <br /> (?) +
Ill. +, Ky. +, N.C. +  and S.C. +
0 +  and 2/5 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
sometimes longer +
widest +, 0.7mm +  and 0.9mm +
4mm +  and 10mm +
subtending +
scabridulous +
lanceolate +
subequal +
membranous +
0.9mm +  and 1.2mm +
uncinate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
3 cm30 mm <br />0.03 m <br /> (60 cm600 mm <br />0.6 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
midlength +
tuberculate +
ovate +, rectangular +  and lanceolate +
membranous +  and coriaceous or indurate +
narrowing +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
concealed +  and prominent +
2 +  and 4 +
2 +  and 1 +
well-developed +
0 +  and 1/2 +
reduced +
8 cm80 mm <br />0.08 m <br /> (25 cm250 mm <br />0.25 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
dry +  and fleshy +
not prolonged +
unisexual +  and bisexual +
laterally compressed +  and terete +
0.3 cm3 mm <br />0.003 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Nassella trichotoma +
Nassella +
species +
membranous +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +