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Mexican panicgrass, roughstalk witchgrass, roughstalk wltchgrass, woodland panic

Ghiesbreght's panicgrass, Ghiesbreght's witchgrass

Habit Plants annual; glabrous or hispid, hairs papillose-based. Plants perennial; cespitose.
Culms

11-110 cm, erect to decumbent;

nodes shortly hirsute or glabrous.

40-120 cm tall, 2-3 mm thick, decumbent to erect, branching from the base and the middle nodes;

nodes pilose, hairs spreading;

internodes hirsute, hairs papillose-based.

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.

usually shorter than the internodes, hirsute, lower sheaths more so than those above, hairs papillose-based;

collars densely pilose;

ligules 0.5-4 mm;

blades 16-55 cm long, 0.5-14 mm wide, erect to ascending, abaxial surfaces hirsute, hairs papillose-based, adaxial surfaces densely pilose, midveins prominent and whitish, bases truncate, margins ciliate basally, 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.

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.

2.6-3.4 mm long, 0.9-1.2 mm wide, ovoid, glabrous.

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.

1.4-1.7 mm, to 1/2 as long as the spikelets, acute, 5-7-veined;

upper glumes and lower lemmas similar, exceeding the upper florets by 0.7-0.9 mm, 9-13-veined;

lower florets sterile;

lower paleas 0.5-1.3 mm;

upper lorets 1.7-2.3 mm long, 0.8-1.1 mm wide, smooth, ovoid.

Terminal

panicles 7-35 cm long, 5-23 cm wide, about 1/2 as wide as long, shortly exerted or partially included, lax, open;

axillary panicles smaller, included basally;

primary branches diverging, lower branches solitary, upper branches solitary to subverticillate;

secondary branching primarily in the distal 1/3;

pedicels 1-4 mm, clavate, spreading to appressed.

2n

= unknown.

Panicum hirticaule

Panicum ghiesbreghtii

Distribution
from FNA
AZ; CA; NM; NV; OK; TX; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
TX; PR
[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 ghiesbreghtii grows in low, moist ground, wet thickets, and savannahs, from southern Texas through Mexico, Central America, Cuba, and the West Indies to northern South America.

(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. 466.
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. capillarioides, P. coloratum, P. dichotomiflorum, P. diffusum, P. flexile, 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 E. Fourn.
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