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

1016 POACEAE/PASPALUM
Guadalupe Co. (Turner et al. 2003) near sw margin of East TX; mainly Gulf Prairies and
Marshes and South TX Plains; in the U.S. known only from TX; also Latin America. Jun–Nov.
Paspalum laeve Michx., (smooth), FIELD PASPALUM, FIELD CROWN GRASS. Tufted perennial without
rhizomes or only shortly rhizomatous; culms to ca. 100(–120) cm tall; leaf sheaths glabrous to
pilose; leaf blades sometimes marginally crisped; inflorescence branches (2–)3–6(–8), (2–)4–
10(–12) cm long, the branch axes � unwinged; spikelets 2.4–3.4 mm long, solitary, in 2 rows;
lower glume absent; upper glume and lemma of sterile floret glabrous. Prairies, open woods,
disturbed or moist areas, often on sand; Pineywoods and Post Oak Savannah; also n Gulf Prairies
and Marshes; e U.S. from MA s to FL w to KS and TX. Jul–Oct. While some authorities (e.g.,
Kartesz 1999; Turner et al. 2003; Allen & Hall 2003) do not recognize varieties in this species,
until a detailed study of the group is carried out, we are following Gould (1975b), Jones et al.
(1997), Yatskievych (1999), and Hatch (2002) in recognizing the 3 somewhat overlapping varieties—not
all individuals can be assigned with certainty. The maps in Turner et al. (2003) and the
one presented here do not distinguish varieties.
1. Spikelets 2.7–3.2 mm wide, ca. as wide as long and circular in outline or nearly so _____________ var. circulare
1. Spikelets 2–2.5 mm wide, conspicuously longer than wide, broadly ovate to broadly obovate in
outline.
2. Lower leaf sheaths and lower leaf blades glabrous or with sparse hairs ______________________ var. laeve
2. Lower leaf sheaths and often lower leaf blades moderately to densely hairy _______________ var. pilosum
var. circulare (Nash) Fernald, (circular), ROUND-SEED PASPALUM. Lamar, Liberty, Marion, San
Augustine, and Upshur (BRIT) cos. [P. circulare Nash]
var. laeve, FIELD PASPALUM, SMOOTH PASPALUM. Anderson, Freestone, Henderson, Houston, Jefferson,
Morris, Panola, Rusk, Shelby, Titus, Upshur (BRIT), and Lamar (Carr 1994) cos. This is the
most common variety in East TX.
var. pilosum Scribn., (with long soft hairs), HAIR-LEAF PASPALUM. Panola and Titus (BRIT) cos. [P.
longipilum Nash]
Paspalum langei (E. Fourn.) Nash, (for Johann Martin Christian Lange, 1818–1898, Danish botanist),
RUSTY-SEED PASPALUM, RUSTY-SEED CROWN GRASS, LANGE’S PASPALUM. Cespitose perennial
without rhizomes; culms 30–125 cm tall; ligule ca. 0.6–2 mm long; leaf sheaths and blades glabrous
or with minute pubescence; leaf blades (4–)7–18 mm broad, often conspicuously crisped
marginally; inflorescence branches (1–)2–5, usually 4–10(–13) cm long, the branch axes �
unwinged; spikelets usually 2.2–2.7 mm long, usually paired, appearing in 2 or 4 rows; lower
glume present on some or all spikelets, reduced; upper glume and lemma of sterile floret pubescent,
usually with brownish glandular blotches. Shaded ditches, stream bottoms, moist
woods; s part of East TX; also Gulf Prairies and Marshes, South TX Plains, e Edwards Plateau,
and disjunct to Tarrant Co. (BRIT) in Cross Timbers and Prairies; FL, LA, OK, and TX. Apr–Nov.
[Dimorphostachys langei E. Fourn.]
Paspalum lividum Trin., (lead-colored, bluish gray), LONG-TOM, PULL-AND-BE-DAMNED. Tufted perennial;
culms decumbent to stoloniferous basally, to 70 cm tall but to over 1.5 m long; ligule (1–
)2.2–4.7 mm long; inflorescence branches usually 3–7(–11), (1–)1.5–4(–5) cm long, the branch
axes winged; spikelets 2.2–2.6 mm long, typically paired, usually in 4 rows; lower glume absent;
upper glume and lemma of sterile floret glabrous. Ditches, wet places, muddy coastal areas,
fresh or brackish water; Bexar, Colorado, Harris, Jasper, Jefferson, Orange, Waller, and Wilson
(Turner et al. 2003) cos. on s margin of East TX; mainly Gulf Prairies and Marshes and South
TX Plains, also Burnet and Brown (Turner et al. 2003) cos. near w margin of Cross Timbers and
Prairies; FL, LA, and TX. May–Nov. This species is important for cattle grazing along the Gulf
Coast (Hatch et al. 1999).