Dichanthelium wilcoxianum

(Vasey) Freckmann
Common names: Wilcox’s panicgrass
Endemic
Synonyms: Panicum wilcoxianum
Treatment appears in FNA Volume 25. Treatment on page 449.

Plants cespitose. Basal rosettes poorly differentiated; sheaths glabrous; blades 2-4 cm, narrow, similar to those of the lower cauline leaves, ascending to spreading. Culms 15-35 cm, stiffly erect, all but the upper 2-4 internodes very short; nodes glabrous or with weak, reflexed hairs; internodes purplish-gray, sparsely pubescent; fall phase developing early, forming erect branches from the lower or midculm nodes, each branch terminating in a partially included panicle of 8-16 spikelets, no sterile shoots formed. Cauline leaves usually 3; sheaths hirsute, hairs papillose-based; ligules 0.5-1 mm; blades 4-8 cm long, 2-5 mm wide, all alike, stiffly erect, green to grayish-green, flat, not plicate, sparsely pilose. Primary panicles 3-5 cm long, 2-4 cm wide, ovoid, open, shortly exserted, with 12-32 spikelets; branches short, stiff, spreading; pedicels mostly 4-8 mm, spreading. Spikelets 2.4-3.2 mm long, 0.7-1.2 mm wide, ellipsoid to obovoid, often reddish throughout, short-pubescent. Lower glumes 0.7-1.2 mm, triangular; upper glumes and lower lemmas about equaling the upper florets; upper florets 1.9-2.5 mm, ellipsoid, pointed. 2n = 18.

Distribution

Alta., Man., Sask., Colo., N.Mex., Mont., Minn., Wis., Kans., N.Dak., Nebr., S.Dak., Ill., Ind., Iowa, Okla., Wyo.

Discussion

Dichanthelium wilcoxianum grows in dry prairies, especially in sandy or gravelly openings. It is restricted to the Flora region. The primary panicles, which are produced from mid-May to early June, are partially open-pollinated; the secondary panicles, which are produced in June, and occasionally also in September, are cleistogamous.

Some specimens of Dichanthelium oligosanthes subsp. scribnerianum from the southern Great Plains that have prematurely elongating upper internodes resemble D. wilcoxianum, but they have greenish spikelets that are 1.7-2.4 mm wide, an orange spot at the base of the glumes, and larger basal rosettes.

Selected References

None.

Lower Taxa

None.

"usually distinctly longer and narrower" is not a number."decumbent" is not a number.

... more about "Dichanthelium wilcoxianum"
rounded +  and attenuate +
anatomy +  and kranz +
Mary E. Barkworth +
(Vasey) Freckmann +
1 (?) +  and 3 (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
green +  and grayish-green +
distinct +
4 cm40 mm <br />0.04 m <br /> (8 cm80 mm <br />0.08 m <br />) +
shortly ovate +  and lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
spreading;erect +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
terete +  and compressed +
sometimes longer +
Wilcox’s panicgrass +
branching +  and hollow +
decumbent +  and sprawling +
15 cm150 mm <br />0.15 m <br /> (35 cm350 mm <br />0.35 m <br />) +
Alta. +, Man. +, Sask. +, Colo. +, N.Mex. +, Mont. +, Minn. +, Wis. +, Kans. +, N.Dak. +, Nebr. +, S.Dak. +, Ill. +, Ind. +, Iowa +, Okla. +  and Wyo. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
papillose-based +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Oval (?) +  and Round (?) +
bracteate +  and ebracteate +
purplish-gray +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
cauline +  and basal +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
membranous +
inconspicuous +
1/5 +  and 3/4 +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
complex +  and simple +
concealed +  and prominent +
with weak , reflexed hairs +  and glabrous +
2 +  and 1 +
subterranean +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
dry +  and fleshy +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
hirsute +  and glabrous +
in triplets +  and paired +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
short-pubescent +
12 +  and 32 +
unisexual +  and bisexual +
ellipsoid +  and obovoid +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.52 cm5.2 mm <br />0.0052 m <br />) +
0.7mm +  and 1.2mm +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Panicum wilcoxianum +
Dichanthelium wilcoxianum +
Dichanthelium sect. Linearifolia +
species +
membranous +
15-60 times as long +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
pointed +  and ellipsoid +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
chartaceous-indurate +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +