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

BUCHLOE/POACEAE 861
ticularly in the e 1/2 of the state; s Canada and throughout most of the U.S. Apr–Jun. Native of
Europe. [B. racemosus of authors, not L., B. secalinus var. velutinus (Schrader) W.D.J. Koch] This
species is similar to and possibly hybridizes with B. japonicus. Texas plants of B. secalinus have
been treated as B. racemosus by some authors (e.g., Shinners 1958; Gould 1962, 1969). However,
we are following Gould (1975b), Hatch et al. (1990), and Jones et al. (1997) in placing them in B.
secalinus. Hatch (2002) treats B. secalinus as including B. commutatus (see discussion under B.
japonicus). This species is considered to be a noxious weed in OK (Kartesz 1999). � I
Bromus tectorum L., (of houses, in recognition of its common habitat in 18th century Europe—
the thatched roofs of dwellings—Leopold 1949), CHEATGRASS, EUROPEAN CHEATGRASS, CHEAT-
GRASS BROME, DOWNY BROME, DOWNY CHESS, BRONCO GRASS, MORMON-OATS, JUNE GRASS. Annual
10–90 cm tall; lower leaf sheaths usually densely pubescent, the upper glabrous; inflorescence
branches drooping to spreading; spikelets glabrous or pubescent, 12–20(–24) mm long; lemmas
with apical teeth often � conspicuous, ca. 1–3(–5) mm long, with awn usually 10–18 mm long.
Roadsides, railroads, and disturbed sites; widely scattered in TX; s Canada and nearly throughout
the U.S. Apr–May(–Jun). Native of Eurasia; apparently first introduced into the e U.S. ca.
1790, followed by multiple independent introductions in other parts of the country (Novak et
al. 1993; Novak & Mack 2001; Bartlett et al. 2002); in TX since 1945 (Mahler 1988). [B. tectorum
var. glabratus Senn.] The awns can cause mechanical injury to grazing livestock (Burlage 1968).
In some parts of the w U.S., this species is a serious fire hazard—it matures early, dries out
quickly, and burns readily (Klemmedson & Smith 1964). It has altered the fire ecology of some
areas, resulting in a dramatic increase in fire frequency—consequently, there have been decreases
in shrubs and other native vegetation and the formation of virtual monocultures of B. tectorum
(Vitousek et al. 1996; Pimentel et al. 2000). Some authorities (e.g., Novak et al. 1993) suggest this
species is now the most abundant vascular plant species in the Intermountain West, and it has
been called a “devastating plant invader” (Bartlett et al. 2002). It is considered to be a noxious
weed in CO (Kartesz 1999). Two varieties are sometimes recognized (e.g., Gould 1975b; Hatch et
al. 1990) based on lemma pubescence (var. glabratus with lemmas glabrous or scabrous versus
var. tectorum with lemmas soft pubescent). However, we are following Pavlick (1995, ined.),
Kartesz (1999), and Hatch (2002) in not recognizing varieties. � I
Bromus texensis (Shear) Hitchc., (of Texas), TEXAS BROME. Annual 40–75 cm tall, short-lived; inflorescences
narrow, the branches stiffly erect or widely spreading; spikelets ca. 20 mm long;
lemmas with awn usually 6–10 mm long. In shade, thickets; Bexar (TAES), Burleson Co.
(TAMU), and Travis (Gould 1975b) cos. near sw margin of East TX; also Gulf Prairies and
Marshes, South TX Plains, and e Edwards Plateau; endemic to TX (Kartesz 1999; Carr 2002b,
2002c) or possibly also in n Mexico (Pavlick ined.). [Bromopsis texensis (Shear) Holub] E
BUCHLOE Engelm. BUFFALO GRASS
AA monotypic C4 genus endemic to North America. Recent molecular evidence (Columbus et
al. 1998, 2000; Columbus 1999) suggests that Buchloe and a number of other small satellite genera
should be included within an expanded Bouteloua (otherwise, Bouteloua is paraphyletic).
According to Snow (2003c), “Morphologically, the segregate genera differ from Bouteloua only
in their pistillate panicles and spikelets and their reproductive mode, but not in their vegetative
and staminate structures.” However, until confirming evidence is available, we are following
Hatch (2002) and Snow (2003c) in maintaining Buchloe as a distinct monotypic genus. Sex expression
in BUFFALO GRASS appears to be environmentally influenced (e.g., light and nitrogen
levels) (Quinn 2000). (Greek: boubalos, buffalo, and chloë, thus a contraction of Bubalochloë—
Snow 2003c) (subfamily Chloridoideae, tribe Cynodonteae)
REFERENCES: Milby 1971[1972]; Quinn & Engel 1986; Columbus et al. 1998, 2000; Columbus 1999;
Quinn 2000; Snow 2003c.