Dichanthelium aciculare
Dichanthelium portoricense
narrow-leaf panicgrass, needleleaf rosette grass
blunt-glumed panicgrass
15-75 cm, erect;
nodes glabrous or sparsely pubescent;
internodes glabrous or puberulent to pilose basally;
fall phase with erect to spreading culms, extensively branched from the mid- and upper culm nodes, eventually producing flabellate clusters of reduced, flat or involute blades.
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.
3-7;
sheaths shorter than the internodes, glabrous or with soft, ascending, papillose-based hairs;
ligules 0.5-2 mm, of hairs;
lower blades 4-16 cm long, 3-9 mm wide, stiffly ascending to erect, glabrous or sparsely pilose to pubescent, with prominent raised veins, flat or longitudinally wrinkled, blades of the flag leaves often greatly reduced, often involute.
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.
1.7-3.6 mm long, 1.2-1.8 mm wide, obovoid to ellipsoid, biconvex in side view, glabrous or pubescent, bases narrow to attenuate, apices blunt or pointed to beaked.
1.5-2.6 mm, obovoid-pyriform, planoconvex in side view, puberulent, pubescent, or glabrous, attenuate basally, apices usually broadly rounded.
thin, weakly veined, about 1/3 as long as the spikelets, attached to 0.5 mm below upper glumes, clasping at the base, broadly triangular to rounded;
upper glumes with 5-9 prominent veins;
lower florets sterile;
upper florets apiculate.
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.
rosettes poorly differentiated;
blades usually large, ovate to lanceolate, often transitional to the cauline blades.
rosettes well-differentiated;
blades 1.5-6 cm, ovate to lanceolate.
panicles 2-10 cm long, 0.5-7 cm wide, open or contracted, well-exserted.
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.
= 18.
= 18.
Dichanthelium aciculare
Dichanthelium portoricense
Dichanthelium aciculare grows in sandy, open areas in the southeastern United States, the West Indies and the Caribbean, southern Mexico, Central America, and northern South America. It has not been reported from northern Mexico. The primary panicles are open-pollinated (sometimes briefly) and develop from April to June; the secondary panicles are cleistogamous and develop from May into late fall.
The subspecies are often distinct when growing together, perhaps maintained by the predominant autogamy, but they are more difficult to separate over wider geographic areas. Rare, partly fertile putative hybrids with Dichanthelium consanguineum, D. acuminatum, D. ovale, D. portoricense, and (possibly) D. dichotomum apparently lead to some intergradation with these species.
(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.)
1. Primary panicles usually contracted; branches appearing 1-sided; culms sparsely pubescent to almost glabrous | subsp. neurantbum |
1. Primary panicles not contracted; branches not appearing 1-sided; culms usually pubescent, at least on the lower internodes. | → 2 |
2. Spikelets 1.7-2.3 mm long, with blunt apices | subsp. aciculare |
2. Spikelets 2.4-3.6 mm long, with pointed or beaked apices. | → 3 |
3. Spikelets 2.4-3 mm long, not strongly attenuate at the base; lower glumes attached less than 0.2 mm below the upper glumes | subsp. angustifolium |
3. Spikelets 2.9-3.6 mm long, strongly attenuate at the base; lower glumes attached 0.3-0.5 mm below the upper glumes | subsp. fusiforme |
1. Spikelets 1.8-2.6 mm long, usually densely pubescent or puberulent (rarely glabrous); cauline blades 4-7 cm long, 3.5-8 mm wide | subsp. patulum |
1. Spikelets 1.5-2.0 mm long, puberulent to nearly glabrous; cauline blades 2-5 cm long, 2.5-4.5 mm wide | subsp. portoricense |
LA Plants
MD Biodiversity
WildflowerSearch
iNaturalist
USDA Plants Database
