36.
Carex
austrina
Mackenzie, Bull. Torrey Bot. Club. 34: 151. 1907.
Carex muehlenbergii Schkuhr ex Willdenow var. australis Olney ex L. H. Bailey, Proc. Amer. Acad. Arts 22: 141. 1886
Plants without conspicuous rhizomes. Culms 20—90 cm, 1.5—3 mm wide basally, 0.9—1.1 mm wide distally. Leaves: sheaths tight, green, fronts hyaline, yellowish and thickened at mouth; ligules to 3 mm, as long as wide; widest leaf blades 2.5—4.5 mm wide, sometimes papillose adaxially. Inflorescences with (3—)5—10 spikes, 1.5—3.5 cm × 8—15 mm; proximal internodes equaling or shorter than proximal spikes; proximal bracts 1—5 cm; spikes with 8—20 ascending or spreading perigynia. Pistillate scales hyaline or brown with green, 3-veined center, ovate, (2.4—)3—4.3 × (1—)1.6—3 mm, body slightly shorter to longer than perigynium and as wide, apex awned to 1.5—3.5(—4) mm. Anthers 2.2—2.5 mm. Perigynia pale green, pale yellow, or pale brown, 9—15-veined abaxially, 3.5—5 × 2.2—3 mm, margins serrulate distally; beak 0.8—1.2 mm, apical teeth 0.4—0.6 mm. Achenes suborbiculate, 1.9—2.5 × 1.5—2 mm.
Fruiting late spring—early summer. Dry prairies, forests, roadside ditches, often in calcareous soils; 100—500 m; Ala., Ark., Iowa, Kans., Ky., La., Miss., Mo., Nebr., Okla., Tenn., Tex.
