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

POA/POACEAE
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long. Forests, floodplains, along streams; widespread in Pineywoods and scattered in Post Oak
Savannah s to Burleson Co. (Turner et al. 2003); also n Gulf Prairies and Marshes; e U.S. from PA
s to FL w to MI and TX. Mar–May (flowering in spring, despite the common name and specific
epithet). [P. f lexuosa Muhl., not Sm.]
Poa bigelovii Vasey & Scribn., (possibly for J. Bigelow, 1787–1879, professor of botany in Boston,
MA and author of American Medical Botany—1817), BIGELOW’S BLUE GRASS. Glabrous annual;
culms erect or with a geniculate base, to 15–35(–45) cm tall; inflorescences with branches appressed-erect;
spikelets 4–6 mm long; lemma long-pubescent on margins and keel, with long,
kinky, cobwebby hairs at base. Travis Co. (Turner et al. 2003) near w margin of East TX; mainly
Edwards Plateau and Trans-Pecos; sw U.S. from OK and TX w to CA. Feb–Apr.
Poa bulbosa L., (bulbose), BULBOSE BLUE GRASS. Densely tufted, glabrous perennial 20–50 cm tall;
culms swollen at base; florets usually developing into asexual bulbils instead of fruits, often
dark purple at base; lemmas glabrous, strongly veined, the tips prolonged as if sprouting.
Spreading from cultivation at Denton Agricultural Experiment Station (Shinners 1958) near w
margin of East TX; otherwise unknown in TX; no county distribution map is provided; this
species is widely scattered nearly throughout the U.S. (and in s Canada) and is included because
of the likelihood of occurrence and to encourage collectors to look for it in East TX. Apr–May.
Native of Europe. Poa bulbosa is spread by the vegetative bulbils, presumably “by a variety of
means, including road graders, mud on shoes and car tires, water, animals, and wind”
(Yatskievych 1999). Soreng and Kellogg (ined.) treated this species as having two subspecies,
subsp. vivipara (Koeler) Arcang (florets bulbiferous) and subsp. bulbosa (florets producing
caryopses). I
Poa chapmaniana Scribn., (for Alvin Wentworth Chapman, 1809–1899, Florida botanist),
CHAPMAN’S POA, CHAPMAN’S BLUE GRASS. Annual to ca. 30 cm tall; similar to P. annua and sometimes
difficult to distinguish from it; spikelets with cleistogamous florets (anthers very small,
0.3 mm or less long). Lawns, fields, and roadsides, sometimes moist areas; Madison and Polk
(Turner et al. 2003) cos.; cited for vegetational areas 1, 4 and 5 by Gould (1975b) and Hatch
(2002); also Tarrant Co. (Turner et al. 2003) in Cross Timbers and Prairies; rare or poorly collected
in TX; native from NE to IL, KS, and AR, but now extending to the eastern and southern
coastal states (Soreng & Kellogg ined.); e U.S. from DE s to FL w to NE and TX, also MA and NY.
Late fall–spring. This species is very closely related to P. annua and may represent a native
North American phase of that Old World species (Yatskievych 1999). Gould (1975b) suggested
that it is perhaps not specifically distinct from P. annua. According to Yatskievych (1999), the
lemmas of P. chapmaniana remain appressed and the stamens and stigmas are usually not exserted
during flowering. Hence the flowers are usually cleistogamous and self-pollinated.
Poa compressa L., (flattened), CANADA BLUE GRASS. Rhizomatous, mat-forming perennial 10–
70(–80) cm tall; culms and basal leaf sheaths strongly flattened, sharply keeled; inflorescence
branches appressed or only slightly spreading; spikelets 3–8 mm long; lemmas with or without
long hairs at base. Cultivated as a forage and lawn grass, escaping?; Dallas Co. (Turner et al.
2003); also Donley and Lubbock cos. in nw TX and Starr Co. in the South TX Plains (Turner et
al. 2003); otherwise reported in TX (Gould 1975b; Hatch et al. 1990; Hatch 2002) only from vegetational
areas 5, 6, 9, and 10; throughout most of Canada and the U.S. Apr–Aug. Native of
Eurasia (despite the common name). It is reported to cause hay fever (Steyermark 1963). This
species is also planted to stabilize soil and for forage (Soreng & Kellogg ined.). I
Poa pratensis L., (of meadows), KENTUCKY BLUE GRASS, JUNE BLUE GRASS, MEADOW GRASS. Sodforming,
glabrous, rhizomatous perennial 15–100 cm tall; inflorescences typically rather loose,
with at least the lower branches spreading; spikelets 3–6 mm long; lemmas pubescent on keel
and marginal veins, cobwebby at base. Disturbed areas, also appearing occasionally in lawns;