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

642 CYPERACEAE/SCHOENOPLECTUS
Newton (BRIT), and Jasper (Turner et al. 2003) cos.; mainly se U.S. from RI s to FL w to MO and
TX. Jun–Oct. [Scirpus etuberculatus (Steud.) Kuntze] This species was first reported for TX (Hardin
Co.) by Correll (1972a). While not officially designated as such (e.g., TOES 1993; Carr 2002d;
Poole et al. 2002), given its limited distribution in the state, we consider this species to be of conservation
concern in TX. �
Schoenoplectus pungens (Vahl) Palla, (piercing, sharp-pointed), AMERICAN BULRUSH, SWORD-
GRASS, THREE-SQUARE BULRUSH, COMMON THREE-SQUARE, THREE-SQUARE, CHAIRMAKER’S RUSH.
Perennial 0.3–1.2(–2) m tall from long-creeping rhizomes; distal leaf blade 2–5 times longer
than to rarely equaling its sheath; inflorescence of 1–4(–10) spikelets; spikelets 5–20(–23) mm
long; bristles (3–)4–6(–8) per flower; spikelet scales with apices notched (0.3–)0.5–1 mm deep
and awns (0.5–)1.5(–2.5) mm long; achenes unequally lenticular (= biconvex) to slightly
trigonous. Wet soils, sometimes emergent in water; widely scattered in TX; widespread in
Canada and nearly throughout the U.S. Apr–Jul. [S. pungens var. longispicatus (Britton) S.G. Sm.,
Scirpus pungens Vahl, Scirpus pungens var. longispicatus (Britton) Cronquist, Scirpus pungens
var. polyphyllus Boeck., Scirpus americanus of authors, not Pers., Scirpus americanus Pers. var.
longispicatus Britton] Because of nomenclatural confusion, this species in the past was widely
known as Scirpus americanus (e.g., Correll & Johnston 1970), an epithet that belongs to plants
previously called S. olneyi. Schuyler (1974) clarified issues of nomenclature. Hybrids between S.
pungens and S. americanus are known (Smith 2002b). Varieties are sometimes recognized in S.
pungens (e.g., Smith 1995), but pending further study we are following Kolstad (1986b) and
Smith (2002b) in not recognizing infraspecific taxa. This species (apparently referred to as S.
americanus in Burrows and Tyrl 2001) is suspected to be a cause of acute respiratory distress
syndrome (ARDS) in cattle when they are moved from a poor pasture into one with a lush
growth of the species—the cause is thought to be an increase in the level of ruminal tryptophan
which is subsequently converted into toxins causing lung damage (Burrows & Tyrl 2001). �
Schoenoplectus saximontanus (Fernald) J. Raynal, (rocky mountain), ROCKY MOUNTAIN BUL-
RUSH, ROCKY MOUNTAIN CLUB-RUSH. Small annual or perennial 9–65 cm tall; rhizomes inconspicuous,
ca. 1 mm thick; culms cylindric, ridged when dry; 0–2 smaller bracts sometimes
present in addition to the erect bract which appears like a continuation of the culm; inflorescences
with 1–10(–20) spikelets, sessile, sometimes with 1–2 branches; spikelets 5–20 mm long;
scales with a slightly recurved awn ca. 0.2–0.5 mm long; stigmas 3; achenes strongly trigonous,
1.3–1.8 mm long. Damp soils or emergent from water; Austin, Bexar, and Travis (Turner et al.
2003) cos.; in a band from the Panhandle to s TX; sw Canada (B.C.) and scattered in the U.S.—
CA, CO, IL, KS, MO, NE, OH, OK, SD, TX, UT, and WY. Spring–fall. [Scirpus bergsonii Schuyler,
Scirpus saximontanus Fernald, Scirpus supinus L. var. saximontanus (Fernald) T. Koyama] In
addition to normal spikelets, this species often exhibits amphicarpy, “the production of individual
florets wrapped in the leaf sheaths at the stem bases (noticeable only by the long style
protruding from the tip of the leaf sheath)” (Yatskievych 1999). This diminutive species superficially
resembles members of the genus Isolepis (BULRUSH, LATERAL BULRUSH).
Schoenoplectus tabernaemontani (C.C. Gmel.) Palla, (for Jacob Theodore von Bergzabern, died
1590, Heidelberg botany professor who Latinized his name as Tabernaemontanus), GREAT BUL-
RUSH, SOFT-STEM BULRUSH, GIANT TULE, SOFT-STEM CLUB-RUSH. Rhizomatous perennial 1–3(–5) m
tall; culms usually soft, easily compressed; spikelets 5–11(–17) mm long, 15–200 per inflorescence;
bristles 6 per flower; achenes plano-convex or unequally biconvex, 1.5–2.8 mm long. Wet ground,
shallow water around lakes; Robertson (BRIT), Gonzales, Hays, Panola, and Travis (Turner et al.
2003) cos.; widely scattered in TX; throughout Canada and the U.S. May–Jul, occasionally to Oct.
[Scirpus lacustris L. subsp. tabernaemontani (C.C. Gmel.) Syme, Scirpus tabernaemontani C.C.
Gmel., Scirpus validus Vahl] The terete (= round in cross section) fresh culms (observed just below
inflorescence) of this species help distinguish it from the similar S. californicus with bluntly