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

648 CYPERACEAE/SCLERIA
Scirpus georgianus R.M. Harper, (of Georgia), GEORGIA BULRUSH, COMMON BULRUSH. Tufted perennial,
0.5–1.5 m tall, with short rhizomes; leaves usually 9(–12) or fewer, mostly on the lower
half of the culm; sheaths and blades usually not conspicuously cross-septate; inflorescences occasionally
with axillary bulbils; spikelets 2–4(–5) mm or less long; perianth bristles absent or
rudimentary; n = 25, 26, 27 (Schuyler 1967, 1976). Moist or wet soils; Anderson, Dallas, Hunt,
Lamar, Red River, Sabine, San Augustine, Van Zandt, and Walker (Turner et al. 2003) cos., primarily
in n part of East TX; also e Cross Timbers and Prairies; se Canada and widespread in the
e 1/2 of the U.S. Spring. [Scirpus atrovirens Willd. var. georgianus (R.M. Harper) Fernald] Often
in the past included in or treated as a variety of S. atrovirens (e.g., Radford et al. 1968; Godfrey &
Wooten 1979).
Scirpus pendulus Muhl., (pendulous, hanging), RUFOUS BULRUSH. Tufted perennial to 1.5 m tall,
with short rhizomes; leaves 4–8, along most of stem; spikelets (4–)5–11(–12) mm long; n = 20
(Schuyler 1967). Ditches, streambeds, pond margins; widespread in East TX; also e Cross Timbers
and Prairies and Hemphill Co. (BRIT) in the Panhandle; se Canada and widespread in the
U.S., particularly the e 2/3. Apr–Jun. [S. lineatus of TX authors, not Michx.] This species was long
known as S. lineatus; that name is correctly used for the DROOPING BULRUSH (Schuyler 1966), a
species that occurs in the e U.S. from VA s to FL w to LA.
SCLERIA Bergius NUT-RUSH
Monoecious rhizomatous perennials or occasionally annuals, usually less than 1 m tall; culms
(= stems) sharply triangular, leafy; inflorescences terminal and often also axillary, of small,
compact clusters of few spikelets, leafy-bracted at base; staminate and pistillate spikelets often
mixed within a cluster; spikelets few-flowered, the scales spirally arranged; perianth absent;
achenes globose or ovoid to obovoid, usually with a whitish, bony, or crustaceous outer layer,
smooth to variously roughened, without an apical tubercle, often, but not always, on a hardened,
disk-like, ring-like, or 3-lobed (and almost calyx-like) basal pad (= hypogynium).
AA genus of ca. 200 species (Reznicek et al. 2002) of tropical and warm areas. Several centers
of diversity include tropical South America, tropical Africa, and se Asia; many species are endemic
to relatively small areas (Tucker 1987; Mabberley 1997). Because achene characters are
critical in identification to species, care should be taken to collect individuals in fruit. The following
treatment draws significantly on Reznicek et al. (2002). (Greek: skleros, harsh, “the
culms of the type species being bound together into whips for beating slaves in Surinam; often
incorrectly said to be derived from Greek skleria, tough, in reference to the achene walls”—
Tucker 1987)
REFERENCES: Core 1936, 1966; Fernald 1943; Fairey 1967; Kessler 1987; Tucker 1987; Reznicek et
al. 2002; Camelbeke et al. 2003.
1. Achene body smooth or with longitudinal ridges.
2. Achene body subtended by a disk-like, ring-like, or 3-lobed (and almost calyx-like) basal pad,
the base of the achene body itself (not the pad) � circular.
3. Basal pad disk-like or ring-like, without lobes (but tubercles can be present), either with a
rough whitish crust or with 8 or 9 papillose tubercles (use hand lens).
4. Basal pad completely covered with rough whitish crust, without distinct tubercles ___ S. triglomerata
4. Basal pad not covered with rough whitish crust, but with 8 or 9 papillose tubercles ____ S. oligantha
3. Basal pad 3-lobed (almost calyx like), but without either a whitish crust or tubercles.
5. Lowest lateral spikelet cluster spreading or drooping on filiform, flexuous stalk (15–)20–
100 mm long; achene body usually with tufts or lines of spreading, whitish or tawny
hairs on ridges, rarely glabrous; uppermost lateral spikelet cluster with bract (including
sheath) usually 1/4–3/4 the length of terminal internode; species widespread in e part
of East TX ___________________________________________________________ S. muehlenbergii