Carex fissa

Mackenzie

in N. L. Britton et al., N. Amer. Fl. 18: 64. 1931.

IllustratedEndemic
Treatment appears in FNA Volume 23. Treatment on page 283. Mentioned on page 280, 282, 284.
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Culms to 80 cm × 3–8 mm, scabrous. Leaves: sheath fronts not spotted, slightly thickened near hyaline margins, apex convex, membranous, rugose; ligule retuse or rounded, to 3 mm, free limb to 0.2 mm; blades 60 cm × 5 mm, shorter than flowering stem. Inflorescences spicate, 3–7 cm × 15–25 mm, with 10–15 branches, proximal branches not distinctly separate; the proximal internode to 10 mm; bracts setaceous, usually only the proximal conspicuous. Scales hyaline, pale brown, becoming colorless with green midrib, awn usually not longer than the body. Perigynia pale brown, body broadly ovate, 3.2–4 × 2–2.6 mm, base rounded or cordate, apex abruptly contracted to beak; beak 1.3–1.5 mm, 1/3 length of perigynium. Achenes brown, ovate, 1.5–1.9 × 1.2–1.6 mm, dull.

Distribution

V23 480-distribution-map.jpg

Fla., Ga., Kans., Miss., Mo., Okla., Tex.

Discussion

Varieties 2 (2 in the flora).

Carex fissa can be distinguished from other taxa in the section by the conspicuously larger perigynia. The two distjunct varieties appear to be consistently separable by the characteristics provided below and may warrant recognition as distinct species.

Selected References

None.

Key

1 Awn of pistillate scale to 0.5–1.5 mm; perigynia veinless adaxially. Carex fissa var. fissa
1 Awn of pistillate scale to 1–3 mm; perigynia 3–5-veined adaxially. Carex fissa var. aristata