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

bulb panicgrass

Habit Plants annual; hirsute or hispid, hairs papillose-based, often bluish or purplish. Plants perennial; cespitose, rhizomatous, rhizomes short, thin.
Culms

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

nodes sparsely to densely pilose.

50-200 cm tall, 2-3(5) mm thick, with cormlike bases, slightly compressed, erect or geniculate at the lower nodes;

nodes glabrous or pilose;

internodes slightly compressed, glabrous.

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.

longer or shorter than the internodes, keeled, glabrous or pilose, hairs papillose-based near the throat;

ligules 0.5-2 mm, membranous, dissected ciliate;

blades (6)20-65 cm long, 2-15 mm wide, flat, adaxial surfaces glabrous or densely pubescent, particularly basally, occasionally pubescent on both surfaces, hairs papillose-based, bases subcordate to rounded.

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.

9-50 cm long, 1.5-12 cm wide, open;

branches opposite and alternate, straight or flexible, strongly ascending to reflexed;

pedicels 0.5-5 mm, scabridulous, divergent.

Spikelets

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

2.8-4.2(5.4) mm long, 1-2 mm wide, ellipsoid or lanceoloid, often purplish, glabrous, acute or obtuse.

Lower glumes

1.2-3.5 mm, 1/2 - 4/5 as long as the spikelets, 3-5-veined;

upper glumes often longer than the lower lemmas, glabrous, 5-7-veined;

lower florets sterile or staminate;

lower lemmas glabrous;

lower paleas 3-4 mm, sometimes longer than the lower lemmas;

upper florets 3-4 mm long, 1-1.5 mm wide, equaling or surpassing the lower lemmas, dull, pale, finely transversely rugose, lemma apices puberulent.

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, 54, 70, 72.

Panicum capillare

Panicum bulbosum

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
AZ; NM; TX; UT
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 bulbosum grows on gravelly river banks and moist mountain slopes, often in ponderosa pine woodlands, from southern Nevada and Arizona to western Texas and central Mexico. It is an important forage grass and is sometimes cut for hay. Flowering is from July to mid-October. Small plants have been called P. bulbosum var. sciaphilum (Rupr. ex E. Fourn.) Hitchc. & Chase or P. bulbosum var. minor Vasey, but size and other characters integrade completely.

(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. 481.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Agrostoidea > sect. Bulbosa
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. 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. verrucosum, P. virgatum
Subordinate taxa
P. capillare subsp. capillare, P. capillare subsp. hillmanii
Synonyms P. bulbosum var. minor
Name authority L. Kunth
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