13. Schoenoplectus (Rchb.) Palla (bulrush)
(Smith and Yatskievych, 1996)
Plants perennial with rhizomes or
apparently annual and tufted. Aerial stems few to usually many per plant, erect
to ascending, slender to stout, unbranched, glabrous, circular or 3-angled in
cross-section, often finely ridged. Leaves basal or few and alternate below the
middle of the stems, the lowermost 1–3 reduced to bladeless sheaths, glabrous.
Leaf sheath tips mostly strongly oblique with a V-shaped or U-shaped sinus on 1
side, the ligule present, appearing as a short, white, scaly ridge (or
sometimes a thin, white margin at the tip of bladeless sheaths). Inflorescences
appearing lateral, subtended by 1–3 bracts, the main bract erect and stemlike,
composed of 1 to many spikelets, these sessile or nearly so in a headlike
cluster, or in an uneven umbel of several stalked spikelets or clusters of
spikelets. Florets usually 10 to many per spikelet, in an overlapping spiral
pattern, perfect. Spikelet scales ovate to broadly ovate, the tips rounded to
pointed and often with a shallow notch, the midrib usually extended past the
main body of the scale as a short awn. Perianth bristles 2–6 or absent. Stamens
2–3. Styles not expanded at the base during flowering, not forming a tubercle,
but frequently persisting on the fruit as a short beak. Stigmas 2 or 3. Ovaries
and fruits naked, without a perigynium (saclike covering). Fruits biconvex,
sometimes unequally so (1 side more rounded than the other), or 3-angled. About
40 species, nearly worldwide.
Schoenoplectus has been included in
the genus Scirpus in most of the North American botanical literature.
For further discussions of the segregation of genera from Scirpus, see
the treatment of that genus and the review of Missouri bulrushes by Smith and Yatskievych
(1996). The presence of several interspecific hybrids in the genus can confuse
determinations. These hybrids generally have been collected infrequently in Missouri but can be relatively common at sites where two or more species of Schoenoplectus
The seeds of Schoenoplectus species
provide food for waterfowl, which disperse these bulrushes both in mud on their
feet and feathers and as undigested seeds in their droppings.