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bristlegrass, plains bristlegrass, streambed bristlegrass, yellow bristlegrass, yellow foxtail

Chapman's bristlegrass

Habit Plants perennial; cespitose. Plants perennial; cespitose.
Culms

20-100 cm.

40-100 cm, erect, slender;

nodes glabrous.

Sheaths

compressed, glabrous, margins villous distally;

ligules 1-2.5 mm, ciliate;

blades 8-25 cm long, 2-5 mm wide, flat or folded, scabrous on both surfaces.

mostly glabrous, margins ciliate distally;

ligules 0.1-0.4 mm, of stiff hairs;

blades 15-40 cm long, 2-5 mm wide, those of the basal leaves involute, those of the cauline leaves flat, adaxial surfaces sparsely pilose basally.

Panicles

6-15 cm, tightly spikelike, pale green;

rachises scabrous or villous;

bristles usually solitary, 4-15 mm, ascending.

to 35 cm, nodding, slender, interrupted;

rachises scabridulous;

branches 5-20, erect, axes 0.4-3.2 cm, undulating, with 3-12 spikelets in 2 ranks, a single bristle present below the terminal spikelets;

bristles 3-6 mm.

Spikelets

2.2-2.8(3) mm, elliptical.

1.8-2.2 mm, obovate, turgid.

Lower glumes

about 1/2 as long as the spikelets, 3-veined;

upper glumes from 3/4 as long as to equaling the florets, 5-veined;

lower lemmas equaling the upper lemmas, 5-veined;

lower paleas 1/2 - 3/4 as long as the upper paleas, lanceolate;

upper lemmas apiculate, finely and transversely rugose;

upper paleas similar.

0.6-0.8 mm, about 1/3 as long as the spikelets, 3-veined;

upper glumes equaling the upper lemmas, 5-7-veined;

lower lemmas equaling the upper lemmas;

lower paleas absent;

upper lemmas finely and transversely rugose;

anthers 0.9-1.1 mm.

2n

= 54, 68, 72.

= unknown.

Setaria leucopila

Setaria chapmanii

Distribution
from FNA
AR; AZ; CO; FL; NM; OK; TX
[WildflowerSearch map]
[BONAP county map]
from USDA
[BONAP county map]
Discussion

Setaria leucopila grows in the southwestern United States and northern Mexico. It is the most common of the perennial "Plains bristlegrasses."

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

Setaria chapmanii is native to soils of coral or shell origin in the Florida Keys, the Bahamas, Cuba, and the Yucatan Peninsula, Mexico. The absence of the lower palea makes S. chapmanii unusual in subg. Paurochaetium.

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

Source FNA vol. 25, p. 548. FNA vol. 25, p. 545.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Setaria > subg. Setaria Poaceae > subfam. Panicoideae > tribe Paniceae > Setaria > subg. Paurochaetium
Sibling taxa
S. adhaerans, S. arizonica, S. barbata, S. chapmanii, S. corrugata, S. faberi, S. grisebachii, S. italica, S. liebmannii, S. macrosperma, S. macrostachya, S. magna, S. megaphylla, S. palmifolia, S. parviflora, S. pumila, S. rariflora, S. reverchonii, S. scheelei, S. setosa, S. sphacelata, S. texana, S. verticillata, S. verticilliformis, S. villosissima, S. viridis
S. adhaerans, S. arizonica, S. barbata, S. corrugata, S. faberi, S. grisebachii, S. italica, S. leucopila, S. liebmannii, S. macrosperma, S. macrostachya, S. magna, S. megaphylla, S. palmifolia, S. parviflora, S. pumila, S. rariflora, S. reverchonii, S. scheelei, S. setosa, S. sphacelata, S. texana, S. verticillata, S. verticilliformis, S. villosissima, S. viridis
Synonyms Paspalidium chapmanii
Name authority (Scribn. & Merr.) K. Schum. (Vasey) Pilg.
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