Carex sect. Stellulatae
brown at base, exceeding leaves.
basal sheaths not fibrous;
sheath fronts membranous, sheaths of proximal cauline leaves smooth or very weakly transversely rugose, sheaths of distal leaves with at least narrow hyaline or white-hyaline band;
blades V-shaped in cross section when young, widest 0.8–5 mm wide, glabrous.
racemose, with (1–)2–10 spikes;
bracts sheathless, with inconspicuous blades, at least (1.5–)2 times as long as wide;
lateral spikes gynecandrous, pistillate, or staminate, sessile, without prophylls;
terminal spike gynecandrous, pistillate, or staminate.
spreading, at least the proximal, veined on abaxial face, veined or veinless on adaxial face, stipitate, broadly ovate to lanceolate, usually plano-convex (to slightly biconvex in C. exilis and C. interior), base rounded to cordate, with spongy tissue, margins acutely angled, apex ± abruptly beaked, glabrous;
beak 0.25–1.6 mm, with abaxial suture, margins often serrulate, apex shortly bidentate.
biconvex, much smaller than bodies of perigynia;
styles deciduous.
pistillate scales with apex obtuse to acute or cuspidate.
2.
Carex sect. Stellulatae
Species ca. 15 (8 in the flora).
Carex sect. Stellulatae is a difficult section in which differences among species can be subtle and identification may require careful observation of perigynium shape and size. Perigynia in the section rapidly narrow towards the apex of the spikes, obscuring the shape differences among species. The perigynium or two just above the staminate portion of the spikes are sometimes misshapen. Therefore, for identification purposes, it is best to examine the third or fourth perigynium above the staminate part of the spikes.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Spikes usually 1; leaves involute; anthers (2–)2.2–3.6 mm. | C. exilis |
1. Spikes 2–8; leaves flat or plicate; anthers 0.6–2.2(–2.35) mm. | → 2 |
2. Perigynium beak smooth-margined. | C. seorsa |
2. Perigynium beak at least sparsely serrulate-margined. | → 3 |
3. Widest leaves 2.8–5 mm wide. | → 4 |
3. Widest leaves 0.8–2.7 mm wide. | → 7 |
4. Proximal perigynia of spikes mostly 1.1–1.7 times as long as wide, mostly 2.1– 3 mm wide. | C. atlantica |
4. Proximal perigynia of spikes (1.5–)1.7–3 times as long as wide, mostly 1.2–2 mm wide. | → 5 |
5. Longer pistillate scales 2.1–3.1 mm. | C. echinata |
5. Longer pistillate scales 1.1–2.2 mm. | → 6 |
6. Inflorescences mostly 1.5–3 cm, the proximal 2 spikes separated by 1.3–9.5 mm. | C. wiegandii |
6. Inflorescences mostly 3–8.5 cm, the proximal 2 spikes separated by 10–40 mm. | C. ruthii |
7. Terminal spikes entirely staminate; anthers (1–)1.2–2.2(–2.35) mm. | C. sterilis |
7. Terminal spikes partly or wholly pistillate; anthers 0.6–2.2(–2.35) mm. | → 8 |
8. Terminal spikes without distinct clavate base of staminate scales, staminate portion, if present, less than 1 mm; anthers (1–)1.2–2.2(–2.35) mm. | C. sterilis |
8. Terminal spikes with distinct clavate base of staminate scales 1–8(–16.5) mm; anthers 0.6–1.6(–2) mm. | → 9 |
9. Proximal perigynia 2–3 mm wide. | C. atlantica |
9. Proximal perigynia 0.9–1.95 mm wide. | → 10 |
10. Proximal perigynia mostly 2.9–4.75 mm, (1.7–)1.8–3.6 times as long as wide; beak mostly 0.95–2 mm, mostly 0.45–0.85 length of body. | C. echinata |
10. Proximal perigynia mostly 1.9–3 mm, 1–2(–2.2) times as long as wide; beak mostly 0.4–0.95 mm, mostly 0.2–0.5 length of body. | → 11 |
11. Perigynia mostly veinless over achene on adaxial surface; perigynium beak conspicuously setulose-serrulate; perigynia often ± convexly tapered from widest point to beak, forming a “shoulder”. | C. interior |
11. Perigynia 1–10-veined over achene on adaxial surface; perigynium beak more sparsely serrulate with definite spaces between the often single teeth; perigynia mostly ± cuneate or even concavely tapered from widest point to beak. | C. atlantica |
