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

1012 POACEAE/PASPALUM
Paspalum bifidum (Bertol.) Nash, (divided into two parts), PITCHFORK PASPALUM, PITCHFORK
CROWN GRASS. Perennial with short rhizomes; rhizomes with ovate, overlapping, densely hairy
scales; culms 60–140 cm tall; ligule ca. 2–4 mm long; leaf sheaths (at least lower ones) with dense
long pubescence; inflorescence branches 2–5, 4–13 cm long, the branch axes � unwinged;
spikelets (3.1–)3.3–4 mm long, mostly paired, widely spaced on the inflorescence branches, the
pairs not overlapping or only slightly so; lower glume often present, reduced; upper glume and
lemma of sterile floret glabrous. Forest margins and openings, loamy sandy or sandy soils; scattered
from Pineywoods and n Gulf Prairies and Marshes w to Dallas and Limestone (BRIT) cos.;
se U.S. from VA s to FL w to MO, OK, and TX (Jun–)Aug–Nov. [P. bifidum var. projectum Fernald]
Allen and Hall (2003) reported that this species grows vigorously following fire.
Paspalum boscianum Flüggé, (for its discoverer, Louis Augustin Guillaume Bosc, 1759–1828,
French naturalist), BULL PASPALUM. Tufted annual; culms (15–)40–70(–100) cm tall; ligule 1–3.2
mm long; inflorescence branches typically 4–12(–15), usually 3–8 cm long, the branch axes
winged; spikelets paired, typically in 4 rows, usually 2–2.2 mm long; lower glume absent; upper
glume and lemma of sterile floret glabrous. Ditches, edges of fields, disturbed areas; Jefferson
Co. (Gould 1975b) near the s margin of the Pineywoods; also reported from the Gulf Prairies and
Marshes (Gould 1975b; Hatch 2002), but we have seen no confirming specimens; its status in
TX is unclear; se U.S. from MD s to FL w to AR and TX, also PA. Late summer–fall. While not
officially designated as such (e.g., TOES 1993; Carr 2002d; Poole et al. 2002), given its limited
distribution in the state, we consider this species to be of conservation concern in TX. �
Paspalum conjugatum P.J. Bergius (jointed in pairs, wedded), SOUR PASPALUM, SOUR CROWN GRASS.
Stoloniferous perennial; culms to ca. 80 cm tall; ligule 0.5–0.8 mm long; inflorescence branches
usually 2, a third sometimes present, 2.5 to ca. 13 cm long, the branch axes � unwinged; spikelets
solitary, 1.3–1.7(–1.9) mm long; lower glume absent; upper glume and lemma of sterile floret
marginally pilose. Disturbed areas, forest margins; Liberty Co. (Brown 28310, SBSC—identification
confirmed L. Brown); a cultivated Hardin Co. collection—McLeod, TAES—was erroneously
cited by Turner et al. 2003 and apparently by Allen and Hall (2003); the Digital Flora of Texas
Herbarium Specimen Browser (2002) also cited Cameron Co. at the s tip of TX, and Hatch et al.
(1990) cited the Gulf Prairies and Marshes; se U.S. from FL w to TX. Jul–Nov. Allen and Hall
(2003) noted that the species is sometimes used as a lawn grass. While not officially designated
as such (e.g., TOES 1993; Carr 2002d; Poole et al. 2002), given its limited distribution in the state,
we consider this species to be of conservation concern in TX. �
Paspalum convexum Humb. & Bonpl. ex Flüggé, (domed, with rounded surface), MEXICAN
PASPALUM, LATIN AMERICAN CROWN GRASS. Tufted annual; culms 10–53 cm tall; ligule 2–4.1 mm
long; inflorescence branches 1–4(–5), (2–)3–4(–7) cm long, the branch axes flattened but
unwinged or nearly so; spikelets paired, often appearing to be in 3 or 4 rows, usually (2.1–)2.3–
2.6(–3) mm long; lower glume absent; upper glume and lemma of sterile floret minutely appressed-pubescent.
Sandy roadsides, disturbed areas; Jasper Co. (Silveus 7384, TAES); Gould
(1975b) indicated that the species was “known in Texas from a single collection made on a
sandy roadside site 10 miles north of the city of Jasper in Jasper Co.” We have seen no additional
TX specimens; LA, MS, and TX. Late summer–fall. Native from Mexico and the Caribbean
islands to Brazil (Hall & Allen 2003). I
Paspalum dilatatum Poir., (dilated, widened, expanded), DALLIS GRASS, PASPALUM GRASS, WATER
PASPALUM, GOLDEN CROWN GRASS. Clump-forming perennial from hardened knotty base; culms
low-spreading to erect, 25–120(–175) cm long; lower leaf sheaths pilose, the upper glabrous except
at summit; ligule 1.5–3(–3.8) mm long; inflorescence branches 2–8, 3–12 cm long, the
branch axes only slightly winged; spikelets mostly paired, appearing in 4 rows, (2.3–)2.9–4 mm
long, with long hairs around the margin, usually with short pubescence on the faces; lower
glume absent; upper glume and lemma of sterile floret abruptly pointed beyond the blunt fruit.