1. Hypoxis hirsuta (L.) Coville (yellow star grass)
104 a, b; Map 416
H. hirsuta f. villosissima Fernald
Plants perennial, with corms, lacking the odor of onion or garlic. Aerial stems
2–25 cm long, unbranched below the inflorescence, erect, sparsely to densely
hairy. Leaves 2–6, basal, 6–30 cm long, linear, with 5–9 main veins, sparsely
to densely hairy. Inflorescences at the tips of the aerial stems, irregular
umbels of 2–6 flowers, sometimes reduced to a single flower, subtended by 1–2
small, linear bracts when young. Flowers with stalks 3–25 mm long, ascending to
spreading, not replaced by bulblets. Perianth 5–13 mm long, spreading, the
sepals and petals attached to the top of the ovary, ovate to narrowly oblong or
nearly linear, the inner (upper) surface yellow, glabrous, the outer (under)
surface yellowish green in bud to usually yellow at flowering, hairy. Stamens
6, attached to the top of the ovary, free from the perianth. Style 1, short,
slightly thickened near the tip, the stigma 3-lobed, the lobes receptive on the
inner surface. Ovary inferior, with 3 locules, each with 3–5 ovules, hairy.
Fruits 3–6 mm long, ovoid, capsulelike but indehiscent, with papery walls. 2n=28.
April–May, rarely reblooming through the summer until October.
Common nearly throughout Missouri, but apparently absent from the Mississippi
Lowlands Division (eastern U.S. and adjacent Canada west to Minnesota and
Texas). Mesic to dry upland prairies, glades, exposed bluff tops, dry upland
forests, and old fields.
This species is quite variable in both the size of the plants and the size of
the flowers. Other unusual features include the indehiscent, dry fruits with
shiny, black, ovoid to globose seeds covered with tiny bumps or spines, and
anthers that diverge in the lower half, giving the stamens an “arrowhead-like”