Dichanthelium portoricense |
Dichanthelium linearifolium |
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blunt-glumed panicgrass |
linear-leaf panicgrass, linear-leaf rosette-panicgrass, panic à feuilles linéaires, slim-leaf rosette grass, slimleaf panicgrass, slimleaf panicum |
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Habit | Plants usually densely cespitose. | Plants cespitose. | ||||
Culms | 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. |
10-50 cm, very slender, erect to drooping, lower 3-8 internodes telescoped together, less than 2 cm, upper 2 internodes elongated; nodes bearded; internodes pubescent to almost glabrous; fall phase developing a dense mass of erect blades and foreshortened branches arising from the basal nodes, terminating in small, narrow secondary panicles that are enclosed within the sheaths, with 6-15 spikelets. |
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Cauline leaves | 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. |
2-4; sheaths longer than the internodes, glabrous or pilose with dense, fine, papillose-based hairs; ligules about 0.5 mm; blades 5-20 cm long, 2-5 mm wide, stiffly ascending to erect, green to grayish-green, glabrous or densely pilose, apices long-tapering, lower blades shorter than the upper 2 or 3 blades. |
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Spikelets | 1.5-2.6 mm, obovoid-pyriform, planoconvex in side view, puberulent, pubescent, or glabrous, attenuate basally, apices usually broadly rounded. |
2-3.2 mm long, 0.8-1.4 mm wide, ellipsoid, not turgid, sparsely pubescent. |
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Lower glumes | 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. |
0.6-1.1 mm, ovate-triangular; upper glumes and lower lemmas exceeding the upper florets by about 0.2 mm before flowering, subequal in fruit, slightly pointed at maturity, upper florets 1.7-2.3 mm, ovoid-ellipsoid, minutely umbonate. |
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Basal | rosettes well-differentiated; blades 1.5-6 cm, ovate to lanceolate. |
rosettes poorly differentiated; blades similar in shape to the lower cauline blades, narrow, ascending. |
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Primary | 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. |
panicles 4-10 cm long, 2-6 cm wide, long-exserted, with 12-70 spikelets; branches and pedicels spreading. |
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2n | = 18. |
= 18. |
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Dichanthelium portoricense |
Dichanthelium linearifolium |
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Distribution |
AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NY; OH; OK; PA; RI; SD; TN; TX; VA; VT; WI; WV; WY; MB; NB; NS; ON; QC; SK
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Discussion | 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.) |
Dichanthelium linearifolium grows in dry, open woodlands, rock outcroppings, and sandy areas. It is restricted to the Flora region. The primary panicles are briefly open-pollinated, produced from May to early June; the secondary panicles are cleistogamous, produced from late June through July (rarely in fall). Plants in the northern United States and Canada tend to be shorter and more spreading, subglabrous, and to have spikelets 2-2.6 mm long; they have been called Panicum werneri Scribn., but do not merit taxonomic recognition. In the southwestern part of its range, especially in the Ozarks, most plants of D. linearifolium are tall, erect, densely pilose, with very elongated blades and spikelets often 2.6-3 mm long; they may hybridize with D. perlongum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 441. | FNA vol. 25, p. 449. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Lancearia | Poaceae > subfam. Panicoideae > tribe Paniceae > Dichanthelium > sect. Linearifolia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Panicum portoricense | Panicum werneri, Panicum linearifolium var. werneri, Panicum linearifolium | ||||
Name authority | (Desv. ex Ham.) B.E Hansen & Wunderlin | (Scribn.) Gould | ||||
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