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bitter beachgrass, bitter panicgrass, bitter panicum

long-beak witchgrass, slender panicgrass

Habit Plants perennial; rhizomatous, rhizomes stout, glabrous and glaucous throughout. Plants perennial; cespitose from a knotty crown, hirsute, hairs papillose-based or glabrous.
Culms

20-250 cm tall, 3-10 mm thick, erect or decumbent, simple or branched from the lower nodes;

nodes glabrous;

internodes glabrous, glaucous.

30-75 cm tall, 1-2 mm thick, terete to slightly compressed, erect or ascending, stiff, often bent at the nodes, simple or sparingly branched;

nodes densely pubescent.

Sheaths

shorter or longer than the internodes, not keeled, glabrous;

collars often glaucous and purplish;

ligules 1-5 mm;

blades 7-50 cm long, 2-13 mm wide, erect or ascending, firm, thick, flat basally, more or less involute towards the apices.

shorter than or equaling the internodes, rounded, hirsute, green or tinged with purple, margins ciliate;

ligules 0.5-1 mm;

blades 12-30 cm long, 2-12 mm wide, stiffly erect or ascending, flat, pubescent, sometimes sparsely so, hairs papillose-based, bases truncate, apices attenuate.

Panicles

10-80 cm long, 2-17 cm wide, contracted, slightly nodding;

primary branches whorled or opposite, strongly ascending to appressed;

pedicels 0.5-15 mm, appressed to slightly divergent.

terminal, 15-30 cm long, 10-12(26) cm wide, usually shortly exserted, scarcely overtopping the blades;

rachises hispid, sometimes glabrous basally;

primary branches alternate or opposite, divergent, secondary branches divergent, most abundant on the distal 1/3 of the primary branches, with 1-3 spikelets;

pedicels 2-20 mm, confined to the distal 1/3 of the branches;

pulvini poorly developed, shortly pilose.

Spikelets

4-7.7 mm long, 1.5-2 mm wide, narrowly ovoid, glabrous, acuminate;

lower florets staminate.

5-6.5 mm long, 1-1.2 mm wide, glabrous, long-acuminate.

Glumes

and lower lemmas relatively thick;

lower glumes 2.8-4 mm, 1/2 - 4/5 as long as the spikelets, 3-9-veined, apices of the midveins sometimes scabridulous;

upper glumes and lower lemmas extending 1.5-3 mm beyond the upper florets, apices stiffly gaping;

upper glumes 3.9-7.6 mm, 5-9-veined;

lower lemmas slightly shorter than the upper glumes, 7-9-veined, lower paleas 3-7 mm, oblong-hastate, folded over the anthers;

lower florets staminate;

upper florets 2.4-3.9 mm long, 1-1.8 mm wide, narrowly ovoid to oblong, glabrous, smooth, shiny, lemma margins clasping the paleas only at the base.

Lower

glumes 2-3 mm, about 1/2 as long as the spikelets, attached about 0.4 mm below the upper glumes, 5-7-veined, acute to obtuse;

upper glumes and lower lemmas 5-6 mm, exceeding the upper florets by 3-4 mm, 9-13-veined;

lower florets sterile;

lower paleas 1.5-2 mm, acute;

upper florets 1.6-2 mm long, 1-1.1 mm wide, smooth, chestnut brown when mature.

2n

= 36, 54.

= 36.

Panicum amarum

Panicum capillarioides

Distribution
from FNA
AL; CT; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NM; NY; PA; RI; SC; TX; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Panicum amarum grows in the coastal dunes, wet sandy soils, and the margins of swamps, along the Atlantic Ocean and the Gulf of Mexico from Connecticut to northeastern Mexico. It is also known, as an introduction, from a few inland locations in New Mexico, North Carolina, and West Virginia, as well as in the Bahamas and Cuba.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Panicum capillarioides grows in sandy grasslands, oak savannahs, and rangelands from southern Texas to northern Mexico.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Rhizomes short or ascending; culms often bunched and decumbent, usually more than 120 cm tall; lower glumes with 3-5 less evident veins, the midvein smooth distally; spikelet density high; panicles with 2 or more main branches per node; spikelets 4-5.9 mm long
subsp. amarulum
1. Rhizomes horizontally elongate; culms mostly solitary, less than 150 cm tall; lower glumes with 7-9 prominent veins, the midvein scabridulous distally; spikelet density moderate; panicles with 1 or 2 main branches per node; spikelets 4.7-7.7 mm long
subsp. amarum
Source FNA vol. 25, p. 472. FNA vol. 25, p. 464.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Repentia Poaceae > subfam. Panicoideae > tribe Paniceae > Panicum > subg. Panicum > sect. Panicum
Sibling taxa
P. anceps, P. antidotale, P. bergii, P. bisulcatum, P. brachyanthum, P. bulbosum, 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
P. amarum, P. anceps, P. antidotale, P. bergii, P. bisulcatum, P. brachyanthum, P. bulbosum, P. capillare, 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. amarum subsp. amarulum, P. amarum subsp. amarum
Name authority Elliott Vasey
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