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serrated tussock, serrated tussockgrass, yass tussockgrass

Andean tussockgrass, tropical needlegrass

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.

40-80 cm tall, 1.5-2.5 mm thick, erect, internodes glabrous;

nodes 2-3, 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;

collars mostly glabrous, with tufts of hair at the sides, hairs 0.5-1 mm;

ligules 0.1-0.3 mm, glabrous, truncate;

blades 12-25 cm long, 1.5-2.5 mm wide, flat to convolute, pubescent.

Panicles

8-25 cm, open, lax, sparse;

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

pedicels 3-12 mm.

10-20 cm, open;

branches 1-3 cm, ascending to somewhat spreading, scabridulous, with 1-8 spikelets;

pedicels 1-8 mm, pubescent.

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, 10-15 mm long, 1.5-2 mm wide, narrowly lanceolate, 3-veined, keeled, keels scabrous;

florets 6-8 mm long, 0.9-1.1 mm wide, terete, widest near or slightly above midlength;

calluses 1.5-2.5 mm, sharp, strigose;

lemmas papillose-tuberculate, constricted and purplish below the crown, midveins and exposed marginal veins pubescent over the proximal 2/3, glabrous between the veins at maturity;

crowns about 1 mm long, about 0.5 mm wide, conspicuous, more or less straight-sided, purple, rims with 1-1.5 mm hairs;

awns 30-50 mm, clearly twice-geniculate, terminal segment straight;

anthers 3-4 mm in putatively chasmogamous florets, 0.3-0.5 mm in cleistogamous florets, both ranges sometimes present within a panicle.

Caryopses

about 1.2 mm, oblong, dark brown.

about 3 mm.

2n

= 36.

= unknown.

Nassella trichotoma

Nassella manicata

Distribution
from FNA
IL; KY; NC; SC
[BONAP county map]
from FNA
CA
[BONAP county map]
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 manicata is native to Ecuador, Chile, Argentina, and Uruguay, growing on the foothills of the Andes Mountains. It is established in three California counties, growing in disturbed sites, including grazed meadows and old gold tailings. It has also been recorded from Mississippi; it is not known whether the Mississippi population has persisted.

Nassella manicata resembles N. leucotricha and N. pulchra. It differs from both in its shorter florets and more strongly developed crowns. It was misidentified as Nassella formicarum (Delile) Barkworth in the Jepson Manual (Barkworth 1993).

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

Source FNA vol. 24, p. 177. FNA vol. 24, p. 174.
Parent taxa Poaceae > subfam. Pooideae > tribe Stipeae > Nassella Poaceae > subfam. Pooideae > tribe Stipeae > Nassella
Sibling taxa
N. cernua, N. chilensis, N. lepida, N. leucotricha, N. manicata, N. neesiana, N. pulchra, N. tenuissima, N. viridula
N. cernua, N. chilensis, N. lepida, N. leucotricha, N. neesiana, N. pulchra, N. tenuissima, N. trichotoma, N. viridula
Name authority (Nees) Hack, ex Arechav. (E. Desv.) Barkworth
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