Panicum tenerum

Beyr. ex Trin.
Common names: Blue-joint panicgrass
Treatment appears in FNA Volume 25. Treatment on page 480.
Revision as of 03:09, 30 July 2020 by imported>Volume Importer
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Plants perennial; cespitose, with short, knotted rhizomes. Culms 40-100 cm, erect, simple or branching from the lower nodes; nodes glabrous; internodes glabrous. Sheaths shorter than the internodes, usually glabrous, lower sheaths sometimes pilose at the summit, hairs papillose-based; ligules 0.1-0.4 mm; blades 4-19 cm long, 1.5-4 mm wide, mostly involute at maturity, erect, firm, abaxial surfaces usually glabrous, adaxial surfaces often sparsely pilose, particularly basally. Panicles 3-12 cm long, less than 1 cm wide, contracted, with few spikelets; branches 1-4 cm, few, ascending-appressed; ultimate branchlets 1-sided; pedicels 0.5-3 mm, scabridulous, appressed, usually with a few slender hairs at the apices. Spikelets 1.8-2.8 mm long, 0.8-1 mm wide, usually subsessile, lanceoloid to narrowly ovoid, green, often purplish-stained, glabrous, acute. Lower glumes 0.9-3 mm, 1/2 - 2/3 as long as the spikelets, 1-3-veined, not keeled over the midveins, acute or obtuse; upper glumes and lower lemmas subequal, 5-7-veined, midveins not keeled, acute to short-acuminate, occasionally gaping at the apices; lower florets sterile; lower paleas about 1/2 - 2/3 as long as the lower lemmas; upper florets 1.1-1.8 mm long, 0.6-0.8 mm wide, 2/5 – 3/4 as long as the spikelets, lustrous, usually brownish, apices glabrous; upper lemmas thick, stiff, clasping the upper paleas throughout their length. 2n = 20.

Distribution

Puerto Rico, Ga., Tex., La., Ala., N.C., S.C., Miss., Fla.

Discussion

Panicum tenerum grows in wet or moist, sandy (often peaty) soil, depressions in pine savannahs, bogs, marshes, pond margins, and interdunal swales. Its range includes the Atlantic and Gulf coastal plains of the United States, the Antilles, Bahamas, and Central America. Panicum tenerum exhibits numerous features of the widespread and polymorphic P. rigidulum, particularly P. rigidulum subsp. pubescens.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."varying" is not a number.

... more about "Panicum tenerum"
acute +, obtuse +, rounded +  and attenuate +
anatomy +  and kranz +
Robert W. Freckmann +  and Michel G. Lelong +
Beyr. ex Trin. +
1 (?) +  and 3 (?) +
keeled +  and rounded +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
4 cm40 mm <br />0.04 m <br /> (19 cm190 mm <br />0.19 m <br />) +
pubescent +  and glabrous +
filiform +  and ovate flat +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
spikelike +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
not developed +
terete +  and compressed +
sometimes longer +
Blue-joint panicgrass +
small green +
branching +  and simple +
compressed +
40 cm400 mm <br />0.4 m <br /> (100 cm1,000 mm <br />1 m <br />) +
woody +  and hard +
Puerto Rico +, Ga. +, Tex. +, La. +, Ala. +, N.C. +, S.C. +, Miss. +  and Fla. +
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 +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
membranous +
inconspicuous +
1/2 +  and 2/3 +
obtuse +, acute +  and not keeled +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
1/2 +  and 2/3 +
complex +  and simple +
acute +  and short-acuminate +
concealed +  and prominent +
2 +  and 1 +
3cm +  and 12cm +
subterranean +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
scabridulous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
dry +  and fleshy +
in triplets +  and paired +
purplish-stained +  and green +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
unisexual +  and bisexual +
acute +, lanceoloid +  and narrowly ovoid +
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 +
Gramineae +
Panicum tenerum +
Panicum sect. Tenera +
species +
membranous +
stipitate +  and sessile +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
2/5 +  and 3/4 +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
pubescent +  and glabrous +
rugose +  and verrucose +
chartaceous-indurate +  and rigid +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +