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

KOELERIA/POACEAE 963
Andropogoneae, it is characterized by C4 photosynthesis (Kellogg 2000a). Several species are
considered significant weeds (Watson & Dallwitz 1992). (Named for Ferrante Imperato, 1550–
1625, of Naples, Italian naturalist and apothecary) (subfamily Panicoideae, tribe
Andropogoneae)
REFERENCES: Gabel 1982, 2003; Allen et al. 1991; Johnson & Shilling 1998; King & Grace 2000;
Lippincott 2000; Matlack 2002; Van Loan et al. 2002.
Imperata cylindrica (L.) Raeusch., (cylindrical, in reference to the shape of the inflorescence),
COGON GRASS, BLADY GRASS, COGON, LALANG, ALANG-ALANG, COTTON GRASS, KUNAI, SATIN-TAIL.
Strongly rhizomatous, tufted perennial usually 1 m or less tall, rarely taller; culms erect; leaf
blades (1–)3–11(–28) mm wide, with whitish midvein markedly off-center, scabrous marginally,
the cauline blades reduced; ligule membranous, 3.5 mm or less long; inflorescence a terminal,
narrowly cylindrical, silky, whitish panicle, usually 6–22 cm long, to 3.5 cm wide; inflorescence
branches appressed, not disarticulating, the spikelets falling from pedicels at maturity; spikelets
2.6–5.5 mm long, unawned, in pairs of 1 short-pedicelled and 1 long-pedicelled, otherwise
alike, with 2 florets (lower sterile, upper fertile); base of spikelet (callus) with a tuft of hairs (6–
15 mm long) longer than spikelet; stamens 2; filaments not dilated basally. Disturbed areas (e.g.,
roadsides); Brazos (Wolfe s.n., TAES, specimen collected on grounds of maintenance building at
Texas A&M Univ.) and Tyler (Van Loan et al. 2002—reported by U.S. Geologic Survey, voucher
not seen) cos.; no county distribution map is provided; se U.S. in SC and from FL w to e TX.
Typically Mar–May or in fall, flowering often initiated by stressful conditions (e.g., burning, cutting,
mowing, drought, soil disturbance). Native from the Old World tropics to the Mediterranean.
[Lagurus cylindricus L.] This species has only recently been reported from TX, but given
its reputation as a harmful invasive, it should be watched for and eliminated if found. COGON
GRASS was introduced to the U.S. accidently (at Mobile, AL in 1911 in shipping crates where the
grass was used as a packing material) and intentionally (by the USDA for use as forage and erosion
control, and as an ornamental grass) (Johnson & Shilling 1998; King & Grace 2000; Kaczor
2003). However, this species is an aggressively rhizomatous invasive weed that displaces other
vegetation, is low in nutritive value and palatable to few animals (the leaf margins are scabrous
and have silica crystals), and can alter the natural fire regime (Mabberley 1997; Lippincott 2000;
Van Loan et al. 2002). It is a noxious weed in FL, HI, and NC, and it is also a U.S. federal noxious
weed (Kartesz 1999; USDA Natural Resources Conservation Service 2002). Some authorities
(e.g., Gabel 2003) consider it “one of the world’s 10 worst weeds,” possibly even worse than
KUDZU (Kaczor 2003). In the tropics, extensive areas become densely infested with COGON
GRASS, resulting in fire-prone monocultures due to the extremely flammable foliage and the
fire-resistant underground rhizomes; such areas are difficult to reclaim with other types of vegetation
(Van Loan et al. 2002). The diminutive cultivar ‘Red Baron,’ which is available commercially,
is non-weedy even though individual shoots may revert to the aggressive form (Gabel
2003). A related species, Imperata brasiliensis Trin., BRAZILIAN SATIN-TAIL, native to Central and
South America, is also both a noxious weed in FL and a U.S. federal noxious weed (Kartesz 1999;
USDA Natural Resources Conservation Service 2002). It can be distinguished by its flowers
having a solitary stamen and the filament being dilated basally. I�
KOELERIA Pers. DOG-TAIL GRASS, KOELER’S GRASS
AA cosmopolitan C3 genus of about 35 species of awnless perennials which grow in dry grasslands
and rocky soils (Standley ined.). Some authorities (e.g., Clayton & Renvoize 1986) suggest
it is related to Tr i s etum, and hybrids with that genus are known (Watson & Dallwitz 1992).
Annual species similar to Koeleria but with awned lemmas have sometimes been segregated
into the genus Lophochloa (e.g., Jonsell 1980) or more recently into Rostraria, as done here following
Clayton and Renvoize (1986), Mabberley (1997), Kartesz (1999), Hatch (2002), and
Standley (ined.). Other authorities, however, do not consider the differences worthy of generic