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common panicgrass, common witchgrass, old witch grass, panic capillaire, witch grass, witch panicgrass

warty panicgrass

Habit Plants annual; hirsute or hispid, hairs papillose-based, often bluish or purplish. Plants annual; weak, ascending or sprawling.
Culms

15-130 cm, slender to stout, not woody, erect to decumbent, straight to zigzag, simple to profusely branched;

nodes sparsely to densely pilose.

10-150 cm, slender, wiry, erect at first, ultimately decumbent, sprawling, glabrous, often with purple dots and streaks, branching extensively at the base, rooting at the lower nodes.

Sheaths

rounded, hirsute or hispid, hairs papillose-based;

ligules membranous, ciliate, cilia 0.5-1.5 mm;

blades 5-40 cm long, 3-18 mm wide, linear, spreading.

often shorter than the internodes, loose, glabrous, margins short-ciliate;

ligules 0.2-0.5 mm, membranous, erose, ciliate;

blades 5-20 cm long, 3-10 mm wide, thin, flat, glabrous on both surfaces, margins scabridulous, apices long-acuminate.

Panicles

13-50 cm long, 7-24 cm wide, usually more than 1/2 as long as the plants, included at the base or exserted at maturity, disarticulating at the base of the peduncles at maturity and becoming a tumbleweed;

branches spreading;

pedicels 0.5-2.8 mm, scabrous, pilose.

5-30 cm, nearly as wide as long;

branches few, capillary, with a few spikelets distally;

pedicels 0.5-10 mm.

Spikelets

1.9-4 mm, ellipsoid to lanceoloid, often red-purple, glabrous.

1.7-2.2 mm long, about 1 mm wide, ellipsoid or obovoid, glabrous, faintly veined, subacute or obtuse at the apices.

Lower glumes

0.3-0.8 mm, reduced, acute;

upper glumes and lower lemmas subequal or the glumes shorter, distinctly verrucose, with hemispheric warts;

upper florets 1.6-2 mm long, about 1 mm wide, grayish-brown, dull, minutely papillose, acute.

Lower

florets sterile;

lower glumes 1/3– 1/2 as long as the spikelets, 1-3-veined;

upper glumes 1.8-3.1 mm, 7-9-veined, midveins scabridulous;

lower lemmas 1.9-3 mm, extending 0.4-1.1 mm beyond the upper florets, often stiff, straight, prominently veined distally;

upper florets stramineous or nigrescent, sometimes with a prominent lunate scar at the base, often disarticulating before the glumes, leaving the empty glumes and lower lemmas temporarily persisting on the panicles.

2n

= 18.

= 36.

Panicum capillare

Panicum verrucosum

Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK; Virgin Islands
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IL; IN; KY; LA; MA; MD; MI; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WV
[WildflowerSearch map]
[BONAP county map]
Discussion

Panicum capillare grows in open areas, particularly in disturbed sites such as fields, pastures, roadsides, waste places, ditches, sand, and rock crevices, etc. It grows throughout temperate North America, including northern Mexico. It also grows in Bermuda, the Virgin Islands, and sporadically in South America, and has become naturalized in much of Europe and Asia. It appears to hybridize with P. philadelphicum.

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

Panicum verrucosum grows primarily in open, moist or wet sandy areas bordering swamps, marshes, or lakes or on roadside ditches; it also grows occasionally in open, drier woodlands. It is restricted to the eastern United States and is mostly, but not exclusively, coastal.

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

Key
1. Upper florets without a lunate scar, usually stramineous; lower paleas absent; pedicels and secondary branches strongly divergent
subsp. capillare
1. Upper florets with a lunate scar at the base, usually nigrescent; lower paleas present; pedicels and secondary branches often appressed, varying to narrowly divergent
subsp. hillmanii
Source FNA vol. 25. FNA vol. 25, p. 487.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Phanopyrum > sect. Verrucosa
Sibling taxa
P. amarum, P. anceps, P. antidotale, P. bergii, P. bisulcatum, P. brachyanthum, P. bulbosum, P. capillarioides, 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
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. 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. virgatum
Subordinate taxa
P. capillare subsp. capillare, P. capillare subsp. hillmanii
Synonyms P. debile
Name authority L. Muhl.
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