Dichanthelium leibergii |
Dichanthelium acuminatum |
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Leiberg's panicum, Leiberg's rosette grass, leibergs panicgrass |
hairy panic grass, hairy perennial panicgrass, hairy rosette-panicgrass, hotsprings rosette grass, panic laineux, tapered rosette grass, western witchgrass, woolly panic grass, woolly witchgrass |
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Habit | Plants cespitose, with knotty rhizomes no more than 2 mm thick. | Plants more or less densely cespitose. | ||||||||||||||||||||||||||||||||||||
Culms | 24-80 cm, glabrous or puberulent; nodes sparsely, spreading-pilose; internodes mostly elongated, glabrous or puberulent; fall phase with a few suberect branches from the lower and midculm nodes, blades slightly reduced, secondary panicles partially exserted. |
15-100 cm (rarely taller), usually thicker than 1 mm, weak and wiry or relatively stout and rigid, erect, ascending or decumbent; nodes occasionally swollen, glabrous or densely pubescent, often with a glabrous or viscid ring below; internodes purplish or olive green or grayish-green, to yellowish-green, variously pubescent, with hairs of 2 lengths or glabrous; fall phase erect, spreading, or decumbent, usually branching extensively at all but the uppermost nodes, ultimately forming dense fascicles of branchlets with reduced, flat or involute blades and reduced secondary panicles with few spikelets. |
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Cauline leaves | 3-4; sheaths not overlapping, with ascending papillose-based hairs; ligules 0.3-0.5 mm, membranous, ciliate, cilia longer than the membranous portion; blades 5-15 cm long, 7-13 mm wide, ascending to erect, sparsely to densely pubescent with papillose-based hairs, with 9-11 prominent major veins and 25-50 minor veins, bases truncate to cordate, margins with papillose-based cilia. |
4-7; sheaths usually shorter than the internodes, glabrous or densely and variously pubescent with hairs shorter than 3 mm, margins ciliate or glabrous; ligules and pseudoligules 1-5 mm, of hairs; blades 2-12 cm long (rarely longer), 2-12 mm wide (rarely wider), firm or lax, spreading to reflexed or stiffly ascending, yellowish-green or grayish-green to olivaceous, densely to sparsely and variously pubescent, margins similar or occasionally whitish-scabridulous, margins often with papillose-based cilia, at least basally, bases rounded or subcordate. |
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Panicles | 6-10 cm long, 3-5 cm wide, their length usually less than twice their width, eventually well-exserted, with 20-40 spikelets; branches spreading to ascending. |
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Spikelets | 3.3-3.8 mm long, 1.6-2 mm wide, ellipsoid-obovoid, turgid, pubescent, hairs papillose-based, apices rounded. |
1.1-2.1 mm, obovoid to ellipsoid, yellowish-green to olivaceous or purplish, variously pubescent, obtuse or subacute. |
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Lower glumes | about 1.8 mm, narrowly triangular; lower florets staminate; upper florets mucronate. |
usually 1/4 - 1/2 as long as the spikelets, obtuse to acute; upper glumes and lower lemmas subequal, equaling the upper florets at maturity, or occasionally the upper glumes slightly shorter, not strongly veined; lower florets sterile; upper florets 1.1-1.7 mm long, 0.6-1 mm wide, ellipsoid, obtuse to acute or minutely umbonate or apiculate. |
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Basal | rosettes well-differentiated; blades few, small, ovate to lanceolate. |
rosettes usually well-differentiated; blades ovate to lanceolate. |
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Primary | panicles 3-12 cm, 1/4 - 3/4 as wide as long, usually open, well-exserted, rather dense; rachises glabrous, puberulent, or more or less densely pilose, at least basally. |
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2n | = 18. |
= 18. |
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Dichanthelium leibergii |
Dichanthelium acuminatum |
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Distribution |
IA; IL; IN; KS; MI; MN; MO; ND; NE; NY; OH; PA; SD; WI; AB; MB; ON; SK
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AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; HI; PR; AB; BC; MB; NB; NS; ON; PE; QC; SK
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Discussion | Dichanthelium leibergii grows primarily on prairie relics, but is occasionally found in sandy woodlands. It is restricted to the Flora region. The primary panicles are produced from mid-May through July, the secondary panicles from late June to September. Sterile putative hybrids with D. acuminatum and D. xantho-physum are occasionally found. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Dichanthelium acuminatum is common and ubiquitous in dry to wet, open, sandy or clayey woods, clearings, bogs, and swamps, or in saline soil near hot springs, growing in much of the Flora region and extending into northern South America. It is probably the most polymorphic and troublesome species in the genus. The treatment presented here attempts to delimit the major variants present, but does not fully reflect the intricate reticulate pattern of morphological variation that exists. There is considerable overlap among the nine subspecies recognized and, in addition, there appears to be widespread introgression from other Dichanthelium species, such as D. dichotomum, D. sphaerocarpon, D. ovale, and D. aciculare into the D. acuminatum complex, contributing to the taxonomic difficulties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 416. | FNA vol. 25, p. 422. | ||||||||||||||||||||||||||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Macrocarpa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Lanuginosa | ||||||||||||||||||||||||||||||||||||
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Synonyms | Panicum leibergii | Panicum acuminatum, Panicum lanuginosum | ||||||||||||||||||||||||||||||||||||
Name authority | (Vasey) Freckmann | (Sw) Gould & C.A. Clark | ||||||||||||||||||||||||||||||||||||
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