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Mexican panicgrass, roughstalk witchgrass, roughstalk wltchgrass, woodland panic

long-beak witchgrass, slender panicgrass

Habit Plants annual; glabrous or hispid, hairs papillose-based. Plants perennial; cespitose from a knotty crown, hirsute, hairs papillose-based or glabrous.
Culms

11-110 cm, erect to decumbent;

nodes shortly hirsute or glabrous.

30-75 cm tall, 1-2 mm thick, terete to slightly compressed, erect or ascending, stiff, often bent at the nodes, simple or sparingly branched;

nodes densely pubescent.

Sheaths

shorter than the internodes, greenish to purplish, glabrous or with papillose-based hairs, ciliate on 1 margin, glabrous on the other;

collars hirsute;

ligules 1.5-3.5 mm, of hairs;

blades 3-30 cm long, 3-30 mm wide, flat, usually hirsute or sparsely pubescent, hairs papillose-based, sometimes glabrous, bases rounded to cordate-clasping, margins ciliate, cilia papillose-based, apices acute.

shorter than or equaling the internodes, rounded, hirsute, green or tinged with purple, margins ciliate;

ligules 0.5-1 mm;

blades 12-30 cm long, 2-12 mm wide, stiffly erect or ascending, flat, pubescent, sometimes sparsely so, hairs papillose-based, bases truncate, apices attenuate.

Panicles

9-30 cm long, 5-8 cm wide, erect or nodding, partially included to well-exserted, rachises glabrous or sparsely hispid basally;

primary branches usually alternate to opposite, divergent, secondary branches and pedicels confined to the distal 2/3;

pulvini inconspicuous;

secondary branches appressed;

pedicels 9-27 mm, appressed.

terminal, 15-30 cm long, 10-12(26) cm wide, usually shortly exserted, scarcely overtopping the blades;

rachises hispid, sometimes glabrous basally;

primary branches alternate or opposite, divergent, secondary branches divergent, most abundant on the distal 1/3 of the primary branches, with 1-3 spikelets;

pedicels 2-20 mm, confined to the distal 1/3 of the branches;

pulvini poorly developed, shortly pilose.

Spikelets

1.9-4 mm long, 0.8-1 mm wide, ovoid to almost spherical, often reddish-brown, glabrous, veins prominent, scabridulous, apices abruptly acuminate.

5-6.5 mm long, 1-1.2 mm wide, glabrous, long-acuminate.

Lower glumes

1.3-2.4 mm, 1/2 - 3/4 as long as the spikelets, 3-5-veined;

upper glumes 1.8-3.3 mm, 7-11-veined;

lower florets sterile;

lower lemmas similar to the upper glumes, 9-veined;

lower paleas 0.4-0.9 mm;

upper florets 1.5-2.4 mm long, 0.4-0.8 mm wide, ellipsoid, smooth or conspicuously papillate, shiny, stramineous, often with a lunate scar at the base.

2-3 mm, about 1/2 as long as the spikelets, attached about 0.4 mm below the upper glumes, 5-7-veined, acute to obtuse;

upper glumes and lower lemmas 5-6 mm, exceeding the upper florets by 3-4 mm, 9-13-veined;

lower florets sterile;

lower paleas 1.5-2 mm, acute;

upper florets 1.6-2 mm long, 1-1.1 mm wide, smooth, chestnut brown when mature.

2n

= 36.

Panicum hirticaule

Panicum capillarioides

Distribution
from FNA
AZ; CA; NM; NV; OK; TX; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Panicum hirticaule grows in rocky or sandy soils in waste places, roadsides, ravines, and wet meadows along streams. Its range extends from southeastern California and southwestern Texas southward through Mexico, Central America, Cuba, and Hispaniola to western South America and Argentina.

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

Panicum capillarioides grows in sandy grasslands, oak savannahs, and rangelands from southern Texas to northern Mexico.

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

Key
1. Blades rounded at the base, 3-16 mm wide; lower paleas less than 1/2 as long as the upper florets; panicles erect
subsp. hirticaule
1. Blades cordate, clasping at the base, 4-30 mm wide; lower paleas more than 1/2 as long as the upper florets; panicles often nodding.
→ 2
2. Nodes, sheaths, and blades glabrous or sparsely pilose, hairs papillose-based; culms usually less than 70 cm tall; spikelets 3.2-4 mm long
subsp. stramineum
2. Nodes, sheaths, and blades hirsute, hairs papillose-based; culms robust, usually more than 70 cm tall; spikelets 3-3.3 mm long
subsp. sonorum
Source FNA vol. 25, p. 460. FNA vol. 25, p. 464.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum
Sibling taxa
P. amarum, P. anceps, P. antidotale, P. bergii, P. bisulcatum, P. brachyanthum, P. bulbosum, P. capillare, P. capillarioides, P. coloratum, P. dichotomiflorum, P. diffusum, P. flexile, P. ghiesbreghtii, P. gymnocarpon, P. hallii, P. hemitomon, P. hirsutum, P. lacustre, P. miliaceum, P. mohavense, P. obtusum, P. paludosum, P. philadelphicum, P. plenum, P. psilopodium, P. repens, P. rigidulum, P. tenerum, P. trichoides, P. urvilleanum, P. verrucosum, P. virgatum
P. amarum, P. anceps, P. antidotale, P. bergii, P. bisulcatum, P. brachyanthum, P. bulbosum, P. capillare, P. coloratum, P. dichotomiflorum, P. diffusum, P. flexile, P. ghiesbreghtii, P. gymnocarpon, P. hallii, P. hemitomon, P. hirsutum, P. hirticaule, P. lacustre, P. miliaceum, P. mohavense, P. obtusum, P. paludosum, P. philadelphicum, P. plenum, P. psilopodium, P. repens, P. rigidulum, P. tenerum, P. trichoides, P. urvilleanum, P. verrucosum, P. virgatum
Subordinate taxa
P. hirticaule subsp. hirticaule, P. hirticaule subsp. sonorum, P. hirticaule subsp. stramineum
Synonyms P. pampinosum
Name authority J. Presl Vasey
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