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

1038 POACEAE/POLYPOGON
Lamar (BRIT), San Augustine (on Weches outcrop, SBSC), Brazos, Dallas, Grayson, Fannin, and
Nacogdoches (Turner et al. 2003) cos., also scattered in n and w TX; throughout Canada and the
U.S. Apr–Jun. This species consists of a number of subspecies, only one of which, subsp.
pratensis, occurs in TX. This subspecies is native to Europe despite the common name. Other
subspecies of Poa pratensis are native to the northern regions of North America, often in mountainous
areas (Soreng & Kellogg ined.). While subsp. pratensis is introduced to TX (and considered
a Eurasian native by Correll & Johnston 1970), we are following Tucker (1996), Kartesz
(1999), and Soreng and Kellogg (ined.) in treating the species as native to the U.S. because of the
other subspecies occurring natively farther north. According to Cory (1950b), it was first collected
in n TX in 1949. It is one of the most popular lawn grasses in cooler parts of the country,
is used on golf courses, and is a major forage species in cooler areas of North America. A number
of lawn and pasture strains have been introduced into the U.S. (Gould 1975b; Sutherland
1986; Soreng & Kellogg ined.). Yatskievych (1999) considered it the most economically important
member of the genus. It is reported to cause hay fever in spring (Steyermark 1963).
Poa sylvestris A. Gray, (of woodland), WOODLAND BLUE GRASS, SYLVAN BLUE GRASS. Tufted perennial
30–80(–100) cm tall; inflorescences erect, open, the branches naked of spikelets for 1/2–2/3
their length, the lower branches reflexed in age; spikelets 3–4.5 mm long. Woods in limestone
ravines or low areas; scattered in East TX; not known elsewhere in the state; se Canada (Ont.)
and e U.S. from NY s to FL w to SD and TX. Apr–May.
POLYPOGON Desf. RABBIT’S-FOOT GRASS, BEARD GRASS
Annuals or perennials without rhizomes; ligule a membrane; inflorescence a dense, contracted
panicle; spikelets small, 1-flowered, disarticulating below glumes (sometimes near apex of
pedicel, sometimes near base of pedicel); lemma 1/2–3/4 times as long as the glumes; anthers 3.
AA C3 genus of ca. 18 species (Tucker 1996; Barkworth ined.) of warm temperate areas and
tropical mountains. It is similar to Agrostis, and hybridization is known between the two. However,
in Polypogon disarticulation of the spikelets is below the glumes, while in Agrostis it is
above (Tucker 1996). Both species occurring in East TX are considered significant weeds by
some authorities (e.g., Watson & Dallwitz 1992). (Greek: polys, much, and pogon, beard, presumably
because of the conspicuous awns of some species) (subfamily Pooideae, tribe Aveneae)
REFERENCES: Tucker 1996; Roalson & Allred 1997; Barkworth ined.
1. Glumes with awns 4–10 mm long; inflorescence so dense that its main axis is usually not visible;
plants annual _______________________________________________________________ P. monspeliensis
1. Glumes awnless; inflorescence often interrupted enough that its axis is visible in places; plants
perennial _________________________________________________________________________ P. viridis
Polypogon monspeliensis (L.) Desf., (of Montpellier in s France), RABBIT’S-FOOT, ANNUAL BEARD
GRASS, BEARD GRASS, RABBIT’S-FOOT GRASS, ANNUAL RABBIT’S-FOOT GRASS. Annual, tufted, largely
glabrous; culms 15–75(–100) cm tall, sometimes geniculate at base; ligule (2.5–)4–10(–16) mm
long; inflorescence ca. 2–15(–17) cm long, 1–3 cm broad, appearing bristly-woolly because of
long yellowish awns; spikelets 1.5–2(–2.7) mm long (not including awns); glumes hispidulous,
minutely notched apically, conspicuously awned; disarticulation near apex of pedicel; lemma
0.5–1.5 mm long, with a delicate awn usually 0.5–1 mm long. Low areas, sometimes in shallow
water; throughout TX; s Canada and throughout most of the U.S. Mid-May–Jul. Native of s Europe
and Turkey. A population with vegetatively proliferating spikelets producing plantlets was
reported by Roalson and Allred (1997), who noted that the “lemma, palea, and flower are transformed
into a plantlet arising from inside two normal glumes.” According to Barkworth (ined.),
“In Europe, P. monspeliensis hybridizes with Agrostis stolonifera, producing the sterile
�Agropogon littoralis (With.) C.E. Hubb. and with P. viridis [see below] … but neither hybrid has