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

1056 POACEAE/SETARIA
grasses of the plains. It, therefore, is of greater economic importance as forage and cover than
any of the other perennial species of Setaria in the southwestern United States and northern
Mexico.”
Setaria macrostachya Kunth, (large-spiked), PLAINS BRISTLE GRASS. Tufted perennial 60–120 cm
tall; panicles (6–)8–30 cm long; bristles mostly 10–20 mm long; spikelets 1.9–2.1(–2.3) mm long;
lemma of fertile floret strongly inflated, coarsely rugose. Bexar Co. (Turner et al. 2003) near sw
margin of East TX; mainly Gulf Prairies and Marshes and South TX Plains; also rare in Edwards
Plateau and High Plains; AZ, NM, NV, and TX. May–Nov. A number of the Setaria species (S.
leucopila, S. macrostachya, S. scheelei, S. texana, and S. villosissima) from the s and w parts of
East TX appear to be related and have been referred to as the S. macrostachya complex (Emery
1957a). Some of these species are weakly delimited, and hybridization is suspected (Powell
1994). Kartesz (1999) included S. macrostachya in S. vulpiseta (Lam.) Roem. & Schult., a Latin
American species, presumably following such authors as Renvoize (1984), Webster (1993a), and
Powell (1994). However, Toolin and Reeder (2000), in a critical study of the type specimens, concluded
that the two are separated by a number of characters and are distinct species. We are
therefore following Toolin and Reeder (2000) and Rominger (2003) for nomenclature of this
species.
Setaria magna Griseb., (large), GIANT BRISTLE GRASS, GIANT FOXTAIL GRASS, SALT-MARSH FOXTAIL
GRASS. Coarse annual; culms to 4(–6) m tall, to 1–2(–nearly 3) cm thick at base; panicle 14–45
(–50) cm long and 1.5–3(–5) cm in diam.; bristles 10–20 mm long; spikelets 2–2.5 mm long, disarticulating
below the fertile floret (leaving behind glumes and sterile floret); lemma of fertile
floret smooth and shiny, brown. Wet sand; this species has a special affinity for salt marshes
(Rominger 1962); mainly Gulf Prairies and Marshes, disjunct w to Tarrant Co. (Trinity River
bottom, Fort Worth Nature Center—BRIT) just w of East TX; included because of likelihood of
occurrence in East TX; se U.S. from NJ s to FL w to AR and TX, also AZ. Oct. This is the largest
Setaria species in North America.
Setaria parviflora (Poir.) Kerguélen, (small-flowered), KNOT-ROOT BRISTLE GRASS, KNOT-ROOT
FOXTAIL. Perennial 15–150 cm tall, with hardened base and knotty rhizomes; leaf sheaths
slightly compressed, keeled; leaf blades often pilose near base; panicle dense and stiff, 2–8(–10)
cm long; bristles 4–12 below each spikelet, yellowish, tawny, greenish, or purplish, 5–12 mm
long, antrorsely scabrous; spikelets 1.9–2.8(–3) mm long; lemma of fertile floret rugose. Stream
banks, disturbed sites; widespread in TX; widespread in the U.S. except the nc part of the country.
May–Nov. [S. geniculata (Lam.) P. Beauv.] This native species is extremely similar to the introduced
S. pumila and difficult to distinguish, except that it is a perennial with knotty rhizomes
and usually has smaller spikelets.
Setaria pumila (Poir.) Roem. & Schult., (dwarf), YELLOW BRISTLE GRASS. Annual with fibrous
roots, similar to S. parviflora, differing in its annual habit, slightly larger spikelets, and panicle
with relatively fewer spikelets per verticil; panicles 3–10(–15) cm long; bristles 5–20 below each
spikelet, yellow at maturity, mostly 3–8 mm long, antrorsely scabrous; spikelets 2.7–3.5 mm
long; lemma of fertile floret rugose. Disturbed soils; widespread in TX; s Canada and widespread
in the U.S. Jun–Sep. Native to Europe and Africa. [S. glauca of authors, not (L.) P. Beauv., S.
lutescens (Weigel) F.T. Hubbard] This species has long gone under the name S. glauca, but because
of ambiguity and confusion over type material, S. pumila appears to be the most appropriate
binomial (Clayton & Renvoize 1982). While the epithet pumila is accepted by most recent
authors (e.g., Jones et al. 1997; Kartesz 1999; Rominger 2003), some (e.g., Yatskievych 1999)
still utilize glauca. Subspecific taxa have been described. Kartesz (1999) recognized only subsp.
pallide-fusca (Schumach.) B.K. Simon as occurring in the U.S., while Rominger (2003) indicated
that subsp. pumila was the widespread subspecies, with subsp. pallide-fusca known in North
America only from LA and OR. Jones et al. (1997) did not recognize infraspecific taxa. We are