The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Chilean needlegrass, Chilean tussockgrass

serrated tussock, serrated tussockgrass, yass tussockgrass

Habit Plants perennial; shortly rhizomatous, appearing cespitose, rhizomes slender, somewhat woody. Plants perennial; cespitose, not rhizomatous.
Culms

30-100 cm tall, 0.4-0.7 mm thick, bases somewhat bulblike, erect, geniculate and often branching intra-vaginally at the lower cauline nodes, internodes glabrous;

nodes 5-8+, glabrous.

20-60 cm tall, about 1 mm thick, erect, internodes glabrous;

nodes 2-4, pubescent.

Sheaths

mostly glabrous, throats sometimes ciliate;

collars sparsely hairy, with tufts of hair at the sides, hairs 0.5-1.3 mm;

ligules 0.2-0.3 mm, truncate, usually ciliate;

blades 3-10 cm long, 1-1.5 mm wide, strongly convolute, stiff, abaxial surfaces glabrous, adaxial surfaces with coarse hairs.

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

2-20 cm;

branches 0.4-1.2 cm, with 1-4 spikelets;

pedicels 0.5-4 mm.

8-25 cm, open, lax, sparse;

branches 2-6 cm, with 1-8 spikelets;

pedicels 3-12 mm.

Glumes

subequal, 3-4.5 mm long, 1.1-1.6 mm wide, ovate, 3-veined, glabrous or puberulent, acuminate;

florets 1.6-2.2 mm long, 0.6-0.9 mm wide, obovate to oblong, terete, widest near the top;

calluses 0.2-0.3 mm, obtuse, glabrous;

lemmas glabrous, smooth, lustrous, transition to the crown not evident;

crowns about 0.1 mm long and wide, not differing in texture from the lemmas;

awns 7-10 mm, eccentric, rapidly deciduous;

anthers about 1 mm or 0.3-0.4 mm, florets with longer anthers presumably chasmogamous, those with shorter anthers presumably cleistogamous.

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 mm.

about 1.2 mm, oblong, dark brown.

2n

= 42.

= 36.

Nassella chilensis

Nassella trichotoma

Distribution
from FNA
OR
[BONAP county map]
from FNA
IL; KY; NC; SC
[BONAP county map]
Discussion

Nassella chilensis is an Andean species that was once collected from a ballast dump in Portland, Oregon. It is not established in the Flora region.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Source FNA vol. 24, p. 177. FNA vol. 24, p. 177.
Parent taxa Poaceae > subfam. Pooideae > tribe Stipeae > Nassella Poaceae > subfam. Pooideae > tribe Stipeae > Nassella
Sibling taxa
N. cernua, N. lepida, N. leucotricha, N. manicata, N. neesiana, N. pulchra, N. tenuissima, N. trichotoma, N. viridula
N. cernua, N. chilensis, N. lepida, N. leucotricha, N. manicata, N. neesiana, N. pulchra, N. tenuissima, N. viridula
Name authority (Trin.) E. Desv. (Nees) Hack, ex Arechav.
Web links