Dichanthelium strigosum |
Dichanthelium portoricense |
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cushion-tuft panicgrass, roughhair rosette grass |
blunt-glumed panicgrass |
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Habit | Plants densely cespitose. | Plants usually densely cespitose. | ||||||||||||
Culms | 5-45 cm, slender, erect or spreading; from a dense tuft of predominantly basal leaves, lower internodes short, upper 3-5 internodes elongate; nodes glabrous or bearded; internodes glabrous or pilose; fall phase with spreading culms and branches arising from near the bases forming a dense, flat tuft. |
15-50 cm, slender, wiry; internodes olive green to purplish, densely puberulent or glabrous; fall phase spreading or decumbent, branching extensively from the lower and midculm nodes, producing numerous congested fascicles of reduced, flat or involute blades and reduced secondary panicles. |
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Cauline leaves | 2-4; lower cauline sheaths longer than the internodes, mostly glabrous or pilose with ascending hairs, margins finely ciliate; ligules 0.2-2 mm, at low magnification appearing to be membranous and ciliate, at high magnification evidently of hairs that are coherent at the base; blades 1.5-6 cm long, 3-8 mm wide, lanceolate, glabrous or softly pilose, margins with prominent papillose-based cilia, at least basally. |
4-7; sheaths much shorter than the internodes, densely crisp-puberulent, velvety-puberulent, or glabrous, often ciliate along the margins; ligules shorter than 0.5 mm; blades 2-7 cm long (seldom longer), 2.5-8 mm wide (rarely wider), spreading, firm, flat or slightly involute, without prominently raised veins, not longitudinally wrinkled, densely puberulent or glabrous abaxially, glabrous, sparsely puberulent, or pubescent adaxially, bases subcordate, with papillose-based cilia, margins often whitish and scabridulous. |
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Spikelets | 1.1-2.1 mm, obovoid to broadly ellipsoid, glabrous or pubescent, hairs not papillose-based. |
1.5-2.6 mm, obovoid-pyriform, planoconvex in side view, puberulent, pubescent, or glabrous, attenuate basally, apices usually broadly rounded. |
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Lower glumes | 1/3 - 1/2 as long as the spikelets, acute to obtuse; upper florets 0.8-1.7 mm, ellipsoid, subacute. |
0.6-1.4 mm, thin, weakly-veined, attached about 0.2 mm below the upper glumes, clasping at the base; upper glumes as long as or slightly shorter than the lower lemmas; upper florets 1.4-2 mm, broadly ellipsoid, apices subacute, minutely puberulent. |
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Basal | rosettes poorly differentiated; blades 1-5 cm, lanceolate, grading into the cauline blades. |
rosettes well-differentiated; blades 1.5-6 cm, ovate to lanceolate. |
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Primary | panicles short- to long-exserted; rachises and branches often pilose. |
panicles 2-7 cm long, 2/3 to nearly as wide as long, with relatively few spikelets, exserted; branches flexuous, spreading or reflexed, scabridulous to densely puberulent. |
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2n | = 18. |
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Dichanthelium strigosum |
Dichanthelium portoricense |
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Distribution |
AL; FL; GA; LA; MS; NC; SC; TN; TX; VA; PR
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Discussion | Dichanthelium strigosum extends from the southeastern Flora region south into Mexico, the Caribbean, and into northern South America. The primary panicles are briefly open-pollinated in April or May; the secondary panicles, which are produced from May through November, are cleistogamous. The three subspecies are mostly sympatric and sometimes grow together, with occasional intergradation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Dichanthelium portoricense grows in sandy woods, low pinelands, savannahs, and coastal sand dunes, usually in moist places. Its range extends south from the Flora region into Mexico, the Caribbean, and Mesoamerica. It is a highly variable species with numerous intergrading forms, some possibly resulting from hybridization with other widespread species in the same region, such as D. sphaerocarpon and D. commutatum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 446. | FNA vol. 25, p. 441. | ||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Strigosa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Lancearia | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | Panicum strigosum | Panicum portoricense | ||||||||||||
Name authority | (Muhl. ex Elliott) Freckmann | (Desv. ex Ham.) B.E Hansen & Wunderlin | ||||||||||||
Web links |