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

972 POACEAE/LIMNODEA
swamps; Bowie, Harris, and Liberty (SBSC) cos.; also Johnson Co. (Carr 17715, BRIT) just to the w
of East TX, and Fort Bend Co. (SBSC) in the n part of Gulf Prairies and Marshes; Snow (1997,
2003a) cited no TX specimens; e U.S. from IN s to FL w to MO and TX. Spring–fall. [Diplachne
panicoides (J. Presl) McNeill] Considered by Gould (1975b) to be introduced from Brazil, but
treated more recently as a U.S. native (e.g., Kartesz 1999; Snow 2003a).
Leptochloa virgata (L.) Beauv., (wand-like), TROPIC SPRANGLETOP. Tufted perennial; culms 30–
200 cm tall, usually erect; ligule a membrane 0.2–1 mm long; axils of inflorescence branches
pilose; lemmas awnless or with awns to 3(–11) mm long. Ditches or other moist sites; Bexar
(Snow 1997) and Jefferson (Turner et al. 2003) cos. at extreme s margin of East TX; mainly Gulf
Prairies and Marshes; FL, SC, and TX. May–Nov. [Cynosurus virgatus L., L. domingensis (Jacq.)
Trin.] While Nicora (1995) divided this species into several taxa, Snow (1997) indicated that
though it is highly polymorphic, separation into infraspecific taxa is not warranted. Snow
(2003a) also noted that “Awn length and lemma pubescence vary continuously and independently,
precluding their use in recognizing additional taxa.”
LIMNODEA L.H. Dewey OZARK GRASS
AA monotypic C3 genus of the s United States (Snow ined.). It is related to the perennial genus
Cinna and is sometimes treated in that genus (Tucker 1996; Yatskievych 1999). However,
Brandenburg and Thieret (2000) enumerated numerous differences between these genera (e.g.,
Limnodea is an annual, is smaller, and has longer lemma awns) and concluded that they are
not congeneric. (Name altered from Limnas, a related Old World genus) (subfamily Pooideae,
tribe Poeae)
REFERENCES: Tucker 1996; Brandenburg & Thieret 2000; Snow ined.
Limnodea arkansana (Nutt.) L.H. Dewey, (of Arkansas), OZARK GRASS. Annual 15–60(–100) cm
tall; ligule a lacerate-ciliate membrane 1–2 mm long; leaf blades 2–8 mm wide, glabrous or
more often hispidulous or hispid on upper and lower surfaces; inflorescence a narrow but not
cylindrical panicle, erect or nodding at tip; spikelets 1-flowered, 3–4 mm long excluding awn,
disarticulating below the glumes; lemma usually slightly 2-toothed at apex, awned from back
at or near the base of the 2 teeth, the awn (4–)8–12(–14.5) mm long, geniculate; anthers 3. Prairies
and disturbed areas, calcareous soils, often in sand; throughout most of TX except extreme
w and nw; se U.S. from SC s to FL w to OK and TX, except GA. Mar–Jun. [Cinna arkansana
(Nutt.) G.C. Tucker]
LOLIUM L. RYE GRASS, DARNEL
Annuals or perennials; leaves auricled; ligule a membrane; inflorescence an unbranched spike
(rarely branched) with sessile spikelets in 2 ranks on opposite sides of the axis, the axis remaining
intact, disarticulation occurring above glume and between florets; spikelets 1 per node,
placed with edge (keels of lemmas) against axis of inflorescence, sometimes partially in concavity
in axis, without a glume on that side, (2–)5–15(–22)-flowered.
AA temperate Eurasian C3 genus of 5–8 diploid species (Bulinska-Radomska & Lester 1988;
Loos 1993a; Terrell ined.), including valuable fodder and lawn grasses as well as significant
weeds. Lolium is considered to be of recent origin, and the species are closely related (Charmet
et al. 1997). While previously placed in the tribe Triticeae based on its spicate inflorescence,
Lolium is now recognized as being in the Poeae. A number of workers (e.g., Bulinska-Radomska
& Lester 1988) have noted similarities between the genera Lolium, Festuca, and Vulpia, and
hybrids between Lolium and Festuca are known (Watson & Dallwitz 1992; Terrell ined.).
Darbyshire (1993) suggested that Festuca subgenus Schedonorus, the broad-leaved fescues (including
F. arundinacea) be shifted to Lolium. However, based on recent molecular studies (e.g.,