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

840 POACEAE/BOTHRIOCHLOA
long, shorter on stolons, 3–10(–20) mm wide; inflorescence branches 1–13 cm long; spikelets
(2.2–)2.5–3(–3.5) mm long, acuminate. Moist sandy areas, disturbed places; scattered in s 1/2 of
East TX in Anderson, Bastrop, Brazos, Gonzales, Grimes, Milam, Montgomery, Newton (TAES—
annotated by S. Hatch), and Robertson (Turner et al. 2003) cos.; also n Gulf Prairies and
Marshes; se U.S. from SC s to FL w to TX. May–Nov. [Anastrophus compressus (Sw.) Schltdl. ex
Döll, Milium compressum Sw.] This species is used for lawns in the humid tropics (Clayton &
Renvoize 1986) and is also sometimes cultivated as a fodder. In other circumstances, it is considered
a significant weed (Watson & Dallwitz 1992), and it is included by some authorities
among the world’s worst weeds (Holm et al. 1977).
Axonopus fissifolius (Raddi) Kuhlm., (split-leaved), COMMON CARPET GRASS, NARROW-LEAF CAR-
PET GRASS. Perennial, forming carpets but the flower-bearing culms erect to ascending; culms
20–35(–75) cm long, the nodes glabrous or minutely puberulent; leaf blades 6–17(–28) cm long,
usually 1.5–6 mm wide, flat, blunt; inflorescence branches ca. 2.5–8(–12) cm long; spikelets 1.7–
2.2(–2.6) mm long. Moist sandy woods, margins of wet areas, roadsides; widespread in s and e
portions of East TX; also Gulf Prairies and Marshes; Turner et al. (2003) also mapped a disjunct
site in Sutton Co. on the Edwards Plateau; se U.S. from VA s to FL w to OK and TX. (Feb–)May–
Nov(–Dec). [A. affinis Chase] This species is sometimes used as a lawn or pasture grass, but it can
be weedy (Barkworth 2003h). It is closely related to A. compressus (Crins 1991). Chase (1938)
noted regarding this species [as A. affinis] that the difference from A. compressus “is slight and
there are intergrades, but on the whole specimens may be segregated with relatively few intermediates.”
Axonopus furcatus (Flüggé) Hitchc., (forked, furcate), BIG CARPET GRASS, FLAT CRAB GRASS. Perennial;
culms to 100 cm long; leaf blades to 15(–30) cm long, 3–10(–15) mm wide; inflorescence
branches 3.5–10(–15) cm long; spikelets (3.5–)4–5(–6) mm long, apically acuminate; lemma of
sterile floret and single glume pointed and extending beyond the fertile floret for 1.5–2 mm.
Moist sandy areas, ditches, pond margins; widespread in the Pineywoods and Post Oak Savannah;
also n Gulf Prairies and Marshes; se U.S. from VA s to FL w to OK and TX. May–Nov.
[Anastrophus furcatus (Flüggé) Nash, Panicum furcatum Flüggé]
BOTHRIOCHLOA Kuntze BLUESTEM, BEARD GRASS
Perennials; ligule membranous; inflorescences paniculate with racemose branches; pedicels
and upper internodes of inflorescence branches with a central groove, furrow, or broad membranous
area (this sometimes obscure), often densely villous; spikelets in pairs, one sessile, one
pedicelled; disarticulation at base of sessile spikelet so that associated pedicel and section of inflorescence
branch fall with the sessile spikelet; sessile spikelets 2-flowered, the lower floret
sterile, the upper floret fertile; lower glume dorsally flattened, not enclosing the upper glume;
upper glume with a rounded median keel; lemma of upper floret usually awned, the awn geniculate;
pedicellate spikelets well-developed but often much smaller and narrower than sessile
spikelets, neuter or staminate, awnless.
AA genus of ca. 35 species of tropical to warm-temperate areas of the world (Allred 2003g). A
number of species are strikingly amphitropical in distribution, occurring in both North and
South America (Allred 1981). Some are cultivated for fodder while others are significant weeds.
The genus was formerly treated in a more inclusive Andropogon and appears related to
Dichanthium (Clayton & Renvoize 1986; Kellogg 2000a). Intergeneric hybrids are known with
Dichanthium (de Wet & Harlan 1966, 1970b; Watson & Dallwitz 1992), and some authorities
have suggested combining the two genera (e.g., de Wet & Harlan 1968). Like all members of the
Andropogoneae, Bothriochloa is characterized by C4 photosynthesis (Kellogg 2000a). Allred
(2003g) noted that polyploidy has been “an important mechanism of speciation” in
Bothriochloa. (Greek: bothrion, a shallow pit or trench, and chloa, grass, in reference to the
grooved pedicels or pitted glumes of some species) (subfamily Panicoideae, tribe Andropogoneae)