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

818 POACEAE/AIRA
Late spring–early summer. Native of Eurasia, but Harvey (ined.) suggested “some northern salt
marsh and lakeside populations may be native.” [A. alba L. var. stolonifera (L.) J.G. Sm., A. maritima
Lam., A. palustris Huds., A. stolonifera var. compacta Hartm., A. stolonifera var. palustris
(Huds.) Farw.] This species is sometimes cultivated as a turf grass for lawns (Yatskievych 1999).
According to Barkworth (ined.), “In Europe, P. [Polypogon] monspeliensis hybridizes with
Agrostis stolonifera, producing the sterile �Agropogon littoralis (With.) C.E. Hubb. …” However,
the hybrid has not been reported from North America (Barkworth ined.). I
AIRA L. HAIR GRASS, SILVER HAIR GRASS
AA C3 genus of 8–10 species (Tucker 1996; Mabberley 1997; Wipff ined.) of small annuals of
Europe and the Mediterranean region to Iran; also widely distributed as weeds. Members of this
genus have some of the most open, delicate-appearing inflorescences found among East TX
grasses; the plants are small and easily overlooked. (An ancient Greek name for some grass, perhaps
darnel—Lolium temulentum L.) (subfamily Pooideae, tribe Poeae)
REFERENCES: Brown & Peterson 1984; Tucker 1996; Wipff ined.
Aira caryophyllea L., (like Caryophyllus or Dianthus, Caryophyllaceae, from the tufts of slender
leaves—Fernald 1950a), ANNUAL HAIR GRASS. Delicate tufted annual to ca. 35(–55) cm tall; ligule
1.5–4(–8) mm long, white, membranous; leaf blades usually 0.5(–2.5) mm or less wide; panicles
delicate, very open and diffuse, 4–15 cm long; spikelets 2-flowered, 1.7–3.3(–3.5) mm long excluding
awns; glumes 1.8–3 mm long, longer than the lemmas; lemmas 1.3–2.3(–2.6) mm long,
one or both lemmas with a bent or twisted awn attached near the middle of the back, the awn
ca. 2–4 mm long; paleas shorter than lemmas. Sandy open areas. Gould (1975b), Kartesz (1994,
1999), and Yatskievych (1999) treated var. capillaris as A. elegans. More recently, Hatch (2002)
and Turner et al. (2003) recognized no varieties within A. caryophyllea (which they treated as
including var. capillaris). However, we are following Jones et al. (1997) and the forthcoming
treatment by Wipff (ined.) in recognizing the variation present at the varietal level. The county
distribution map does not distinguish varieties.
1. Lower floret with lemma often awnless (thus usually only one lemma per spikelet awned); pedicels
usually 2–5(–8) times as long as the spikelets; spikelets 1.7–2.5 mm long ____________________ var. capillaris
1. Lower floret with lemma having an awn ca. 2 mm long from near middle of its back (thus both
lemmas of a spikelet awned); pedicels 1–2.5 times as long as the spikelets; spikelets 2–3.3(–3.5)
mm long ___________________________________________________________________ var. caryophyllea
var. capillaris Mutel, (resembling hair, very slender), ANNUAL HAIR GRASS, ANNUAL SILVER HAIR
GRASS. Sandy open areas; Pineywoods and Post Oak Savannah and w in Red River drainage to
Grayson Co. (BRIT); also East Cross Timbers; se U.S. from VA to FL w to NM, also CA, OR, and
WA; Apr–Jun. Native of Europe. [A. capillaris Host, A. elegans Willd. ex Kunth, A. elegantissima
Schur] I
var. caryophyllea, COMMON SILVER HAIR GRASS. Similar to var. capillaris except as noted in the
key. Sandy soils; Gregg, San Jacinto (BRIT), and Lamar (Carr 1994) cos.; reportedly first found in
TX in San Jacinto Co. in 1981 (Brown & Peterson 1984); however, a Gregg Co. collection
(Shinners 20040, BRIT) was made in 1955; e U.S. from NH to GA w to MO and TX, also scattered
in w Canada and w U.S. Apr–May. Native of Europe. I
ALOPECURUS L. FOXTAIL, MEADOW FOXTAIL
Glabrous tufted annuals; ligule membranous, 1.5–7 mm long; leaf blades flat; inflorescence a
dense cylindrical spike-like panicle; spikelets 1-flowered, compressed, disarticulating below
glumes and falling as a unit; glumes equal, awnless; lemmas awned on back below middle, the
awn geniculate; paleas usually absent.