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

944 POACEAE/EREMOCHLOA
widespread in TX; c U.S. from MI s to MS w to WY and NM, also NY and VT. Jul–Dec., sporadically
in the spring. [E. pilifera Scheele, E. trichodes var. pilifera (Scheele) Fernald] Hatch (2002)
recognized var. pilifera. However, we have not been able to find consistent differences and are
thus following Correll and Johnston (1970), Gould (1975b), and Peterson (2003a) in not recognizing
varieties. According to Peterson (2003), this species is sometimes used as an ornamental.
EREMOCHLOA Büse CENTIPEDE GRASS
AA genus of 11 species (Buitenhuis & Veldkamp 2001; Thieret 2003d) native from
Indomalesia (India to New Guinea) to Australia. It is considered by some authorities (e.g., Clayton
& Renvoize 1986) to be related to Coelorachis. The solitary, terminal, 1-sided, spike-like
raceme distinguishes this genus from all other members of the tribe Andropogoneae (Bor 1952b).
Like all members of the Andropogoneae, Eremochloa is characterized by C4 photosynthesis
(Kellogg 2000a). (Greek: eremos, desert, and chloa, grass—Bor 1952b) (subfamily Panicoideae,
tribe Andropogoneae)
REFERENCES: Bor 1952b; Buitenhuis & Veldkamp 2001; Thieret 2003d.
Eremochloa ophiuroides (Munro) Hack., (snake-tailed), CENTIPEDE GRASS. Mat-forming stoloniferous
perennial; culms erect, to 35 cm tall; leaf sheaths sharply keeled; leaf blades (lower ones)
1–5 mm wide, the upper ones reduced or lacking; inflorescence a solitary, terminal, spike-like
raceme ca. 2–6 cm long and ca. 1.5–2.5 mm wide (pencil-like but much smaller in diam.), the
spikelets closely appressed and overlapping scale-fashion along 1 side; spikelets awnless, glabrous,
in pairs, one sessile, one pedicellate; disarticulation at base of sessile spikelet so that associated
pedicel and section of inflorescence axis fall with the sessile spikelet; pedicelled spikelet
usually much reduced (represented by a bristle) or absent (only � flattened pedicel remaining);
sessile spikelets dorsally compressed, 3–4 mm long, 2-flowered, the lower floret staminate, the
upper floret fertile; lower glume winged near apex, making the glume � truncate apically, the
keel with 1–several hook-like spines 0.2–0.3 mm long near base. Roadsides, parking lots, lawns;
Cherokee (BRIT), Angelina, Liberty, Newton (SBSC), Leon (Gould 1975b), and Brazos (Turner et
al. 2003) cos.; according to Gould (1975b) this species is an occasional escape from experimental
plantings, but we are unaware of other TX localities; se U.S. from NC s to FL w to AR and TX,
also MA. Mainly spring–fall. Native of e Asia. [Ischaemum ophiuroides Munro] This species is
used for erosion control and as a lawn grass (Mabberley 1997), particularly in the tropics (Clayton
& Renvoize 1986). Its use as a lawn grass in the southeastern United States dates from ca.
1920 (Thieret 2003d). The extremely slender, spike-like inflorescences superficially resemble
those of Coelorachis (JOINT-TAIL). The common name is in reference to the appearance of the
leafy stolons (Thieret 2003d). I
ERIOCHLOA Kunth CUP GRASS
Annuals or perennials; ligule of hairs to 1–2 mm long; panicle slender, of erect, appressed, spikelike
racemes along a main axis; spikelets each with a small (� 0.5 mm long) cup-like collar or
ring (called the callus) just under the base, solitary or paired, 2-flowered, the lower staminate or
neuter, the upper perfect; disarticulation at base of spikelets; lower glume absent (see note in
synopsis below); upper glume and lemma of sterile floret similar.
AA C4 genus of 20–30 species of tropical and warm areas of the world (Shaw & Smeins 1981;
Shaw et al. 2003). More than two-thirds of the taxa are found in the American southwest and in
the central Andes (Shaw & Smeins 1981). Some species are important pasture grasses while
others are considered significant weeds (Watson & Dallwitz 1992). The small cup-like structure
below the spikelets, known as the callus, is quite unique and distinguishes the genus from
all other members of its tribe (Shaw & Webster 1987). Its anatomical derivation has been studied
in detail (Shaw & Smeins 1979, 1983; Thompson et al. 1990) with conflicting conclusions.