60. Carex bicknellii Britton

Plants with short rhizomes, forming tufts or clumps. Vegetative stems much shorter than the flowering stems, with relatively few leaves. Flowering stems 30–120 cm long, much longer than the leaves. Leaves with well-developed blades mostly 3–6 per flowering stem. Leaf blades 2–25 cm long, 2–4 mm wide, light green to yellowish green. Leaf sheaths often extended past the insertion point of the leaf blade, the ventral side with an elongate, thin, white area and the tip truncate to slightly convex, the ligule about as long as wide or wider than long and U-shaped. Inflorescence straight or nearly so, the 3–7(–9) spikes densely overlapping or the lowermost well spaced along the axis. Spikes 10–18 mm long, 8–12 mm wide, the pistillate portion circular to broadly ovate or obovate in outline, rounded at the tip, with numerous perigynia with somewhat loose to spreading tips, at least the lowermost spike narrowed abruptly to the usually well developed staminate portion, this often inconspicuous in upper spikes. Scales 4.5–6.0 mm long, shorter and narrower than but not hidden by the perigynia, narrowly ovate, bluntly to sharply pointed or (in some specimens of var. opaca) tapered to a delicate, awnlike tip that does not include the midvein, reddish brown or light yellowish brown, often with a green midrib. Perigynia 5.5–7.0 mm long, 2.8–4.8 mm wide, 1.3–2.0 times as long as wide, flat or concave on the ventral side and flat (except over the fruit) or convex on the dorsal side, the main body as long as wide or slightly longer than wide, broadly ovate to nearly circular, widest at or just below the middle, broadly winged to the base, tapered abruptly to a narrow beak with toothed or roughened margins, the ventral and dorsal surfaces lacking papillae, sharply or less commonly faintly 7–14-nerved, pale green to pale brown or orangish brown. Fruits 1.6–2.2 mm long, 1.4–1.7 mm wide, broadly oblong to nearly circular in outline, light brown. 2n=66, 74, 76. April–July.

Scattered nearly throughout Missouri (northeastern U.S. and adjacent Canada west to Nebraska and Texas; disjunct in New Mexico). Bottomland prairies, upland prairies, openings of mesic to dry upland forests, bluff ledges, and margins of ponds; also ditches and moist, disturbed areas.

The distinctive C. hyalina Boott has been collected near the Missouri border in adjacent Arkansas and Tennessee and almost certainly will be found in the state eventually. Although it would key to C. bicknellii in the key to species above, it differs markedly in its ecology and morphology. Carex hyalina occurs in bottomland forests of river floodplains from eastern Texas and Oklahoma to Arkansas, Louisiana, and western Tennessee and Mississippi. It is distinctive in its relatively long-creeping rhizomes and abundant, well-developed vegetative stems at flowering time that are shorter than flowering stems and have numerous leaves. It differs from C. bicknellii in its spikes with only 5–25 perigynia and in its narrower (0.9–1.2 mm) fruits, and also tends to have shorter (mostly 25–60 cm) stems. The perigynia have spreading beaks nearly as long as the broadly elliptic to nearly circular main bodies, giving the spikes a bristly appearance. This species should be searched for in the Mississippi Lowlands Division in remnant, bottomland forests of both the Mississippi and St. Francis River drainages.

Populations of C. bicknellii form a species complex that presently is under study by Anton Reznicek (University of Michigan) and Paul Rothrock (Taylor University). Their studies undoubtedly will result in the recognition of additional species in Missouri. The following discussion of infraspecific variation is based in large part on their as yet unpublished results.