Dichanthelium strigosum |
Dichanthelium wilcoxianum |
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cushion-tuft panicgrass, roughhair rosette grass |
fall panicum, fall rosette grass, Wilcox's panicgrass |
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Habit | Plants densely cespitose. | Plants 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. |
15-35 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. |
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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. |
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. |
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Spikelets | 1.1-2.1 mm, obovoid to broadly ellipsoid, glabrous or pubescent, hairs not papillose-based. |
2.4-3.2 mm long, 0.7-1.2 mm wide, ellipsoid to obovoid, often reddish throughout, short-pubescent. |
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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. |
0.7-1.2 mm, triangular; upper glumes and lower lemmas about equaling the upper florets; upper florets 1.9-2.5 mm, ellipsoid, pointed. |
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Basal | rosettes poorly differentiated; blades 1-5 cm, lanceolate, grading into the cauline blades. |
rosettes poorly differentiated; sheaths glabrous; blades 2-4 cm, narrow, similar to those of the lower cauline leaves, ascending to spreading. |
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Primary | panicles short- to long-exserted; rachises and branches often pilose. |
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. |
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2n | = 18. |
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Dichanthelium strigosum |
Dichanthelium wilcoxianum |
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Distribution |
AL; FL; GA; LA; MS; NC; SC; TN; TX; VA; PR
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CO; IA; IL; IN; KS; MN; MT; ND; NE; NM; OK; SD; WI; WY; AB; MB; SK
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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 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. (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. 449. | ||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Strigosa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Linearifolia | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Panicum strigosum | Panicum wilcoxianum | ||||||||
Name authority | (Muhl. ex Elliott) Freckmann | (Vasey) Freckmann | ||||||||
Web links |