12. Schoenoplectus tabernaemontani (C.C. Gmel.) Palla (great bulrush, softstem bulrush)

Pl. 80 c, d; Map 316

Scirpus tabernaemontani C.C. Gmel.

Scirpus validus Vahl

Schoenoplectus validus (C.C. Gmel.) Á. Löve & D. Löve

Scirpus validus var. creber Fernald

Plants perennial with stout rhizomes. Stems 80–250 cm long, spongy and usually relatively easily crushed, circular or nearly so in cross-section. Leaves 2–4 near the stem bases, the upper 1–2 often with well-developed leaf blades, these 2–10 cm long, flattened to C-shaped in cross-section. Leaf sheaths oblique at the tip, the lower ones chestnut-colored, often split open, the margins of the split transparent and membranous, usually becoming somewhat shredded with age. Inflorescences irregular umbels of usually numerous spikelets, mostly sessile in stalked clusters of 3–7, less commonly more highly branched, the bracts 2–3, the main bract 1–7 cm long, the others reduced and scalelike. Spikelets 5–11 mm long, narrowly ovate to lanceolate in outline, mostly pointed at the tip. Spikelet scales 2–3(–3.5) mm long, broadly oblong-ovate, irregularly fringed and notched at the tip, orangish brown to dark brown, the reddish purple spots and/or short lines (visible under magnification) often present, but not prominent, the midrib not or only slightly extended past the main body of the scale 0.2–0.8 mm, straight or sometimes somewhat bent. Perianth bristles 6, shorter than to slightly longer than the fruits, relatively slender, flattened and straight to contorted or arched, retrorsely barbed. Stigmas 2, less commonly 3 in a few florets. Fruits 1.5–2.3 mm long, ovate to obovate in outline, the tip with a noticeable, narrow beak, unequally biconvex (one side rounded, the other nearly flat) in cross-section, rarely slightly 3-angled, the surface smooth, straw-colored, turning grayish brown or brown, somewhat shiny. 2n=42. May–September.

Scattered to locally common nearly throughout the state (U.S., Canada, south to South America; Caribbean Islands, Europe, Asia). Emergent aquatic on banks of rivers, margins of ponds and lakes, marshes, sloughs, and bottomland prairies; wet depressions along roadsides and railroads.

The name S. tabernaemontani is based upon a type specimen from Europe. American plants are sometimes segregated as S. validus, but there are no clear distinctions between plants from the two continents. In addition to the key characters and the generally softer aerial stems, S. tabernaemontani also tends to have darker stems and a somewhat more open inflorescence with more drooping branches than do S. acutus and S. heterochaetus. For a discussion of putative hybrids between these species, see the treatment of S. acutus..

A single, unusual specimen from Camden County apparently represents a sterile,/> hybrid between S. tabernaemontani and S. pungens. This specimen has the rounded stems of S. tabernaemontani and the congested inflorescence of S. pungens, with spikelet scales somewhat intermediate between the two putative parents.

The seeds and rootstocks of S. tabernaemontani were used for food by Native Americans. The starchy rhizomes were dried and ground into flour and the young growth was eaten raw or boiled.