Panicum hallii

Vasey
Common names: Hall’s witchgrass
Synonyms: Panicum lepidulum
Treatment appears in FNA Volume 25. Treatment on page 466.

Plants perennial; cespitose. Culms 10-100 cm, 2-10 mm thick, erect, simple or sparingly branched basally; nodes sericeous, pilose or glabrous; internodes usually glaucous. Leaves often crowded basally; sheaths rounded, glabrous or hirsute, hairs fragile, papillose-based, margins sometimes ciliate distally; ligules 0.6-2 mm; blades 4-23 cm long, 1-10 mm wide, erect to spreading, flat or sometimes involute (on sterile branches), often curling at maturity, glaucous, abaxial surfaces sometimes with prominent papillae along the midribs, bases rounded or narrowing to the sheaths, margins cartilaginous, ciliate basally, scabridulous elsewhere, apices acute. Terminal panicles 7-31 cm long, 3-15 cm wide; rachises glabrous, tending to break at maturity; branches usually alternate, slender, stiff, ascending to divergent; pedicels 1-15 mm, appressed. Spikelets 2.1-4.2 mm long, 0.8-1 mm wide, usually ovoid, glabrous. Lower glumes 1.2-2.4 mm, 1/2 - 3/4 as long as the spikelets, attenuate; upper glumes and lower lemmas similar, 7-11-veined, acuminate, extending 0.3-1.2 mm beyond the upper florets; lower florets sterile; lower paleas 0.8-2 mm; upper florets 1.5-2.4 mm long, 0.7-1.2 mm wide, ovoid to ellipsoid, smooth, nigrescent. 2n = 18.

Distribution

Okla., N.Mex., Tex., La., Utah, Ariz., Colo.

Discussion

Panicum hallii grows on sandy, gravelly, or rocky land, including roadsides, pastures, rangeland, oak and pine savannahs, chaparral, and moist areas in deserts and on mesas. Its range extends from the southwestern United States to southern Mexico.

Selected References

None.

Key

1 Spikelets 3-4.2 mm long; panicles usually greatly exceeding the blades, with a few spikelets; blades clustered near the base of the plants, ascending, often curling at maturity Panicum hallii subsp. hallii
1 Spikelets 2.1-3 mm long; panicles scarcely exceeding the blades, with relatively crowded spikelets; blades not clustered near the base of the plants, lax, spreading, not curled Panicum hallii subsp. filipes

"decumbent" is not a number."elongated" is not a number."-11-veined" is not declared as a valid unit of measurement for this property.

... more about "Panicum hallii"
puberulent +
anatomy +  and kranz +
Robert W. Freckmann +  and Michel G. Lelong +
1 (?) +  and 3 (?) +
keeled +  and rounded +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
rounded +
swelling +
membranous +
narrowing +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
4 cm40 mm <br />0.04 m <br /> (23 cm230 mm <br />0.23 m <br />) +
pubescent +  and glabrous +
filiform +  and ovate flat +
1mm;10mm +
divergent +  and alternate +
spikelike +
slender +
not developed +
terete +  and compressed +
thick-walled +
sometimes longer +
Hall’s witchgrass +
small green +
branched +  and simple +
not compressed +
10 cm100 mm <br />0.1 m <br /> (100 cm1,000 mm <br />1 m <br />) +
woody +  and not succulent +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Okla. +, N.Mex. +, Tex. +, La. +, Utah +, Ariz. +  and Colo. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
pubescent +  and glabrous +
tuberculate +
unequal +
membranous +
well-developed +
papillose-based +
uncinate +
Oval (?) +  and Round (?) +
bracteate +  and ebracteate +
hollow +  and solid +
coriaceous +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
1/2 +  and 3/4 +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
scabridulous +
complex +  and simple +
concealed +  and prominent +
glabrous +, pilose +  and sericeous +
2 +  and 1 +
subterranean +
pyramidal +
simple +  and compound +
0.1 cm1 mm <br />0.001 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
dry +  and fleshy +
hirsute +  and glabrous +
in triplets +  and paired +
0.21 cm2.1 mm <br />0.0021 m <br /> (0.42 cm4.2 mm <br />0.0042 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
0.1 cm1 mm <br />0.001 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.8mm +  and 1mm +
1 (?) +  and 3 (?) +
compound +  and simple +
fused +  and free +
2 (?) +  and 3 (?) +
dome--shaped +  and triangular +
Panicum lepidulum +
Panicum hallii +
Panicum sect. Panicum +
species +
7 cm70 mm <br />0.07 m <br /> (31 cm310 mm <br />0.31 m <br />) +
3 cm30 mm <br />0.03 m <br /> (15 cm150 mm <br />0.15 m <br />) +
membranous +
stipitate +  and sessile +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
ovoid +  and ellipsoid +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
pubescent +  and glabrous +
rugose +  and verrucose +
chartaceous-indurate +  and rigid +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +