Hypoxis

Linnaeus

Syst. Nat. ed. 10, 2: 986, 1366. 1759.

Common names: Star-grass
Etymology: Greek hypo, under, and oxys, sharp, referring to the pointed bases of the ovaries
Treatment appears in FNA Volume 26. Treatment on page 201. Mentioned on page 55.

Herbs, perennial, scapose, glabrous or sparsely to densely pubescent, often pilose, pubescence including at least some irregularly stellate trichomes, rhizomatous or cormose. Stems subterranean, usually vertical, fleshy. Leaves grasslike; blade linear to setaceous. Scape usually shorter than leaves. Inflorescences depauperate racemes or umbels, borne singly in leaf axils, bracteate. Flowers: tepals 6, spreading, distinct, often greenish abaxially, yellow adaxially, outer usually ± pilose abaxially; anthers 6, spreading, shortly connate at bases; ovary inferior, usually densely pubescent to pilose, sometimes glabrate; style erect. Fruits capsular, crowned by persistent flower parts throughout maturation. Seeds (5–)10–50 per capsule, ± globose, hilum and micropyle prominent, surfaces sharply to bluntly muricate or with rounded pebbling, sometimes with iridescent, membranous coat.

Distribution

Mainly Southern Hemisphere.

Discussion

Species 100 (7 in the flora).

Most species of Hypoxis are in southern Africa. The key to flowering plants presented below will work for most specimens; some specimens have intermediate characteristics and are impossible to identify without seeds. When mature seeds are available, identifications should be confirmed by examination of the seed characters. Relationships among the species in the flora are uncertain and will remain so until a better understanding of the primarily African H. angustifolia complex is reached. Therefore, species are treated here in alphabetical order.

Key

1 Leaves glabrous or nearly so, or with scattered trichomes near base. > 2
1 Leaves sparsely to densely pubescent, at least near base. > 4
2 Leaves 0.3–1 mm wide, hard, stiff; floral bracts 1–7(–12) mm; ovary densely pubescent; seeds with low, rounded sculpturing. Hypoxis juncea
2 Leaves 1–15 mm wide, soft, flexible; floral bracts 1–20(–80) mm; ovary glabrate or sparsely to densely pubescent; seeds muricate. > 3
3 Pedicel usually 2+ times longer than bracts; tepals much longer than ovary; ovary obconic, densely pubescent. Hypoxis hirsuta
3 Pedicel usually shorter than bracts; tepals usually 2 or less times longer than ovary; ovary cylindric, glabrate or sparsely pubescent. Hypoxis curtissii
4 Pedicel usually 2+ times longer than bracts. > 5
4 Pedicel usually less than 2 times as long as bracts. > 6
5 Leaves 1–15 mm wide; seeds coarsely muricate. Hypoxis hirsuta
5 Leaves 0.3–1 mm wide; seeds with low, rounded sculpturing. Hypoxis juncea
6 Pedicel usually longer than bracts; tepals longer than pedicel; anthers 1.5–3.5 mm; (old leaf bases persisting as bristles). Hypoxis rigida
6 Pedicel shorter to longer than bracts; tepals shorter to longer than pedicel; anthers 0.6–2.2 mm. > 7
7 Tepals 1.5–2 times as long as ovary. Hypoxis sessilis
7 Tepals less than 1.5 times as long as ovary. > 8
8 Scape topped by 2 opposite bracts. Hypoxis mexicana
8 Scape topped by 1 bract or, if inflorescences 2- or more-flowered, bracts not opposite. Hypoxis wrightii