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 grow together.

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.