Panicum amarum subsp. amarulum

(Hitchc. & Chase) Freckmann & Lelong
Synonyms: Panicum amarulum
Treatment appears in FNA Volume 25. Treatment on page 472.

Plants with short (usually) or ascending rhizomes. Culms usually 100-250 cm, robust, decumbent, densely bunched (occasionally with more elongated rhizomes and less bunching in the southern part of its range). Panicles usually more than 5 cm wide, spikelet density high; primary branches usually 2 or more per node, smooth to moderately scabrous, usually with quaternary branching. Spikelets 4-5.9 mm; lower glumes 3-5-veined, veins less evident than in subsp. amarum, midvein smooth distally.

Discussion

Panicum amarum subsp. amarulum grows in swales behind the first dune and on sandy borders of wet areas. It extends as far north as northern New Jersey and extends southward into Mexico. It has been introduced to Massachusetts, West Virginia, Cuba, and the Bahamas.

Panicum amarum subsp. amarulum is a fertile tetraploid, and possibly a progenitor of subsp. amarum, with which it intergrades in the Gulf region. Plants that intergrade with P. virgatum are evident in some coastal areas; they may represent hybrids.

Selected References

None.

Lower Taxa

None.

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

puberulent +
scabridulous +
Acute (?) +, Obtuse (?) +, Rounded (?) +  and Attenuate (?) +
anatomy +  and kranz +
Robert W. Freckmann +  and Michel G. Lelong +
(Hitchc. & Chase) Freckmann & Lelong +
1 (?) +  and 3 (?) +
keeled +  and rounded +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
7 cm70 mm <br />0.07 m <br /> (50 cm500 mm <br />0.5 m <br />) +
pubescent +  and glabrous +
filiform +  and ovate flat +
thick;2mm;13mm +
spikelike +
not developed +
terete +  and compressed +
thick-walled +
sometimes longer +
small green +
branched +  and simple +
20 cm200 mm <br />0.2 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
decumbent +  and erect +
100 cm1,000 mm <br />1 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Conn. +, N.J. +, N.Y. +, Del. +, Fla. +, La. +, Md. +, Miss. +, N.C. +, Tex. +, Va. +, W.Va. +, Ala. +, N.Mex. +, Pa. +, R.I. +, Ga. +, Mass. +  and S.C. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
pubescent +  and glabrous +
tuberculate +
unequal +
membranous +
well-developed +
uncinate +
Oval (?) +  and Round (?) +
bracteate +  and ebracteate +
hollow +  and solid +
glaucous +  and glabrous +
scale-like +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
membranous +
inconspicuous +
1/2 +  and 4/5 +
acuminate +, truncate +  and acute +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
oblong-hastate +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
10cm +  and 80cm +
subterranean +
pyramidal +
2 cm20 mm <br />0.02 m <br /> (17 cm170 mm <br />0.17 m <br />) +
simple +  and compound +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
dry +  and fleshy +
opposite +  and whorled +
strongly ascending;appressed +
scabrous +  and smooth to moderately +
glaucous +  and glabrous +
shorter or longer +
not keeled +
in triplets +  and paired +
0.4 cm4 mm <br />0.004 m <br /> (0.77 cm7.7 mm <br />0.0077 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
acuminate +  and ovoid +
0.4 cm4 mm <br />0.004 m <br /> (0.59 cm5.9 mm <br />0.0059 m <br />) +
1.5mm +  and 2mm +
1 (?) +  and 3 (?) +
compound +  and simple +
fused +  and free +
2 (?) +  and 3 (?) +
dome--shaped +  and triangular +
Panicum amarulum +
Panicum amarum subsp. amarulum +
Panicum amarum +
subspecies +
membranous +
stipitate +  and sessile +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.39 cm3.9 mm <br />0.0039 m <br />) +
narrowly ovoid +  and oblong +
0.1 cm1 mm <br />0.001 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0.39 cm3.9 mm <br />0.0039 m <br /> (0.76 cm7.6 mm <br />0.0076 m <br />) +
pubescent +  and glabrous +
rugose +  and verrucose +
chartaceous-indurate +  and rigid +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +