63. Carex cristatella Britton

Pl. 46 a–e; Map 179

Plants with short, inconspicuous rhizomes, forming tufts or clumps. Vegetative stems abundant at flowering time, conspicuous and nearly as long as the flowering stems, the leaves well spaced along the apical half. Flowering stems 30–100 cm long, shorter than to more commonly longer than the leaves. Leaves with well-developed blades mostly 4–6 per flowering stem. Leaf blades 2–40 cm long, 3–7 mm wide, green to yellowish green. Leaf sheaths extended past the insertion point of the leaf blade, the ventral side green nearly to the concave tip, the ligule longer than wide and U-shaped. Inflorescence straight or nearly so, the 6–12 spikes mostly densely overlapping along the axis. Spikes 4–8 mm long, 4–8 mm wide, the pistillate portion circular in outline, rounded at the tip, with numerous dense perigynia with the tips spreading stiffly in all directions, the spike appearing as a spiny ball, the short staminate portion inconspicuous. Scales 1.4–1.9 mm long, much shorter and narrower than and mostly hidden by the perigynia, lanceolate to narrowly ovate, sharply pointed or tapered to a narrow point, greenish white to straw-colored, with a green midrib and lighter margins. Perigynia 2.4–3.9 mm long, 1.1–1.5 mm wide, 2.5–3.0 times as long as wide, flat or nearly so on the ventral side and convex over the fruit on the dorsal side, the main body 1.3–1.9 times as long as wide, lanceolate, widest near the middle, the distance from the tip of the fruit to the tip of the perigynium 0.8–2.2 mm, narrowly winged, the wing tapered abruptly from about the middle of the main body and often ending above the base, tapered gradually to a beak with toothed or roughened margins, the wing ending more or less at the tip of the beak, the ventral and dorsal surfaces lacking papillae, finely 5–9-nerved, light green to pale brown or straw-colored. Fruits 1.4–1.9 mm long, 0.5–0.8 mm wide, narrowly oblong-ovate in outline, light brown. May–July.

Scattered in the northern half of the state, almost entirely restricted to the Glaciated Plains Division (northeastern U.S. and adjacent Canada west to North Dakota and Kansas). Bottomland prairies, moist depressions of upland prairies, sloughs, margins of ponds, and banks of streams, less commonly in openings of bottomland forests; also moist pastures, railroads, and ditches.

Carex cristatella is recognized most easily by its spikes with the tips of the perigynia spreading in all directions, giving them the appearance of spiny balls. Specimens of C. molesta and C. tribuloides sometimes become somewhat distorted when pressed, giving the perigynia a somewhat more spreading appearance than when fresh. In such cases, care should be taken to use other characters to confirm species determinations, such as the appearance of vegetative stems and the size and shape of perigynia and pistillate scales.