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

1058 POACEAE/SETARIA
following the recent treatment by Rominger (2003) for nomenclature and circumscription of
this species. Subspecies pallide-fusca can be distinguished by its smaller spikelets (2–2.5 mm
long) and reddish bristles (Rominger 2003)—it is considered a federal noxious weed (Kartesz
1999; USDA Natural Resources Conservation Service 2002), and also is listed as noxious in FL.
Setaria pumila is known to cause mechanical injury to the mouths of livestock; the bristles easily
penetrate flesh and remain there because of their tiny barbs (Kingsbury 1964). � I
Setaria reverchonii (Vasey) Pilg. subsp. reverchonii, (for Julien Reverchon, 1837–1905, a French-
American immigrant to Dallas and important botanical collector of early TX), REVERCHON’S
BRISTLE GRASS. Tufted erect perennial 20–80 cm tall; culm bases hard, swollen; leaf sheaths pilose
on margins and at summit; leaf blades scabrous; panicle (9.5–)25.3–32.6(–64.8) cm long;
bristles (short) present only at base of terminal spikelets (sometimes below a few other spikelets)—plants
thus resembling Panicum; lemma of fertile floret conspicuously rugose. Rock outcrops
or gravelly soils on limestone; Bell, Bexar, DeWitt, Hill, McLennan (BRIT), Comal, Dallas,
Hays, and Travis (Turner et al. 2003) cos. on w margin of East TX; mainly w 2/3 of TX; NM, OK,
and TX. Apr–Jun, Sep. [Panicum reverchonii Vasey] Correll and Johnston (1970) treated this species
in the genus Panicum. Fox and Hatch (1999) recently studied this and related species of
Setaria and named a new subgenus, Reverchoniae. They also reduced S. ramiseta (Scribn.) Pilg.,
which occurs just to the s and w of East TX, to a subspecies of S. reverchonii (subsp. ramiseta
(Scribn.) W.E. Fox). The two subspecies can be distinguished as follows:
1. Spikelets usually (2.9–)3–3.4(–4.5) mm long; penultimate leaf blades (3.6–)11.7–13.3(–28.6) cm
long, usually tapering to an extremely narrow base, often involute; bristles shorter than to longer
than spikelets (rarely � 6 mm long) _____________________________________________ subsp. reverchonii
1. Spikelets (2.4–)2.7–2.8(–3.4) mm long; penultimate leaf blades (3–)6.8–7.6(–12.1) cm long, not
or only slightly narrowing toward base, flat; bristles usually shorter than the spikelets ________ subsp. ramiseta
Setaria scheelei (Steud.) Hitchc., (for Adolf Scheele, 1808–1864, German botanist and clergyman),
SOUTHWESTERN BRISTLE GRASS, SCHEELE’S BRISTLE GRASS. Coarse tufted perennial 70–130
cm tall; panicle usually strongly tapered from a narrow apex to a wider base; bristles (10–)15–35
mm long; spikelets 2.1–2.6 mm long; lemma of fertile floret rugose. Fencerows, ravines, open
woods, often in shade; widespread in s 1/2 of TX except for the Pineywoods; in the U.S. known
only from TX and NM; also Mexico. May–Nov.
Setaria texana Emery, (of Texas), TEXAS BRISTLE GRASS. Tufted perennial 15–70(–90) cm tall;
panicle very narrow, ca. 5 mm wide (excluding bristles); bristles 3–10 mm long; spikelets 1.8–2.1
mm long; lemma of fertile floret finely rugose. In partial shade, beneath trees or brush, thickets,
typically in sandy loam soils; Bexar and Wilson (Turner et al. 2003) cos. near extreme sw edge
of East TX; also widespread in s and sw TX; endemic to TX and n Mexico (Gould 1975b). Flowering
throughout the year under appropriate conditions.
Setaria verticillata (L.) P. Beauv., (whorled), HOOKED BRISTLE GRASS, BUR BRISTLE GRASS, BUR FOX-
TAIL GRASS, ROUGH BRISTLE GRASS, BRISTLY FOXTAIL, FOXTAIL GRASS. Annual to 100 cm tall; leaf
sheath margins glabrous to ciliate; panicle 5–15 cm long, the branches in whorls; bristles
retrorsely scabrous, 4–7 mm long; spikelets 1.5–2.3 mm long; lemma of fertile floret finely rugulose.
Disturbed places; Bexar, Brazos, Burleson, DeWitt (Turner et al. 2003), and Travis (Carr
2002a) cos.; scattered mainly in s 1/2 of TX; s Canada and widespread in much of the U.S. except
the far se. Native to Europe and Africa. Spring–summer. [S. adhaerans (Forssk.) Chiov.] The
retrorsely scabrous bristles can cling tenaciously to clothing (Clayton & Renvoize 1986). Some
authorities (e.g., Gould 1975b; Kartesz 1999; Rominger 2003) recognize S. adhaerans as a separate
species. However, based on morphological similarity, we are following Hatch (2002) in including
it within S. verticillata. Clayton (1980) indicated that S. adhaerens is one of a number
of variants of S. verticillata “which do not seem to merit specific rank.” Rominger (2003) separated
the 2 using the following characters. I