keys to the vascular plants of east texas - Botanical Research ...

904 POACEAE/DICHANTHELIUM
2003) cos.; sw margin of East TX sw through Edwards Plateau and Trans-Pecos; in the U.S.
known only from TX; also Mexico and Guatemala. Mar–Jun, occasionally again late summer–
fall. [Panicum pedicellatum Vasey]
Dichanthelium polyanthes (Schult.) Mohlenbr., (many-flowered), MANY-FLOWER PANIC GRASS,
LEAFY ROSETTE GRASS, LEAFY DICHANTHELIUM. Culms 30–80(–95) cm tall; ligule minute or apparently
absent; blades of larger culm leaves 15–30 mm wide, cordate at base, ciliate only near
the base, with white cartilaginous margins; inflorescence axis glabrous; spikelets 1.3–1.7 mm
long. Wooded areas, near streams, roadside ditches; Angelina, Grimes, Hardin, Leon (BRIT), Liberty,
Montgomery, San Jacinto, and Tyler (SBSC) cos. in the Pineywoods and Post Oak Savannah;
e U.S. from VT s to GA w to MO, OK, and TX. Apr–Jun, again late summer–fall. [D.
sphaerocarpon (Elliott) Gould var. isophyllum (Scribn.) Gould & C.A. Clark, D. sphaerocarpon
var. polyanthes (Schult.) Gould, Panicum microcarpon Muhl., Panicum microcarpon var.
isophyllum Scribn., Panicum polyanthes Schult., Panicum sphaerocarpon Elliott var. isophyllum
(Scribn.) Angelo, Panicum sphaerocarpon var. polyanthes (Schult.) Sherif] This species sometimes
hybridizes with D. sphaerocarpon (Freckmann & Lelong 2003a) and has often been
treated as a variety of that species (e.g., Gould 1975b; Hatch 2002). Gould (1975b) indicated that
the two taxa seem to completely intergrade.
Dichanthelium portoricense (Desv. ex Ham.) B.F. Hansen & Wunderlin, (of Porto [Puerto] Rico),
HEMLOCK ROSETTE GRASS, BLUNT-GLUME PANIC GRASS. Culms 15–50 cm tall; culm internodes and
usually leaf sheaths puberulent to short pilose but without long spreading hairs; leaf blades
2.5–6(–8) mm wide; spikelets 1.3–2.4(–2.6) mm long, attenuate at base. Low woods, bogs; Lee,
Angelina (BRIT), Bastrop, Polk, and Sabine (Turner et al. 2003) cos.; also Gulf Prairies and
Marshes; se Canada and widespread in the e U.S. w to IA and TX. May–Jun. [D. portoricense
subsp. patulum (Scribn. & Merr.) Freckmann & Lelong, D. sabulorum (Lam.) Gould & C.A.
Clark var. patulum (Scribn. & Merr.) Gould & C.A. Clark, Panicum patulum (Scribn. & Merr.)
Hitchc., Panicum portoricense Desv. ex Ham., Panicum sabulorum Lam. var. patulum (Scribn. &
Merr.) C.F. Reed] While this species has often been treated as Dichanthelium or Panicum
sabulorum (e.g., Gould & Clark 1978; Kartesz 1999), Lelong (1984) and Hansen and Wunderlin
(1988) indicated that D. sabulorum is a South American species that is not conspecific with the
taxon here treated as D. portoricense. Yatskievych (1999—as Panicum) and Freckmann and
Lelong (2003a) also used the name D. portoricense. Freckmann and Lelong (2003a) suggested
that this species possibly hybridizes with D. commutatum and D. sphaerocarpon; they further
noted that it can resemble D. aciculare. Some authorities (e.g., Freckmann & Lelong 2003a) recognize
infraspecific taxa in this species; however, based on the limited material available to us,
we are not recognizing varieties or subspecies. Likewise, Hatch (2002) did not formally treat infraspecific
taxa. For those wishing to distinguish these, the following key from Freckmann and
Lelong (2003a) may be helpful:
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
Dichanthelium ravenelii (Scribn. & Merr.) Gould (for Henry William Ravenel, 1814–1887, botanist
and planter of South Carolina), RAVENEL’S PANIC GRASS. Culms 30–80 cm tall, stout, 2–3 mm
thick, erect, with bearded nodes, with a glabrous ring below the beard; leaf sheaths short-pilose;
ligule of hairs usually 2–4(–5) mm long; leaf blades 8–16(–18) mm wide, densely velvety-pubescent
beneath, pilose toward base on upper surface and on margins, otherwise glabrous or
nearly so; spikelets 3.7–4(–4.3) mm long, purplish at base. Sandy woods, dry areas; widespread
in East TX; also n margin of Gulf Prairies and Marshes; e U.S. from MD s to FL w to MO, OK, and
TX. Apr–Jun, again late summer–fall. [Panicum ravenelii Scribn. & Merr.] Gould (1975b) noted