Jepsonia

Small

Bull. Torrey Bot. Club 23: 18, plate 256. 1896 ,

Etymology: For Willis Linn Jepson, 1867–1946, California botanist
Treatment appears in FNA Volume 8. Treatment on page 118. Mentioned on page 43, 44, 46, 119, 120, 132.
Herbs, (acaulescent, heterostylous), not rhizomatous, not stoloniferous; caudex branched or unbranched, ovoid or flat, cormlike, fleshy, without scales. Flowering stems (usually appearing in autumn or winter after basal leaves have withered), erect or ascending, leafless, 3–28 cm, stipitate-glandular, slightly viscid. Leaves in basal rosette and cauline; stipules present; petiole stipitate-glandular; blade ovate to suborbiculate or orbiculate-reniform, shallowly lobed, base cordate, ultimate margins crenate with callous-apiculate teeth, apex obtuse to rounded, surfaces hairy; venation palmate. Inflorescences cymose panicles, (origin of inflorescences not readily resolvable), 2–17-flowered, sometimes flowers solitary, bracteate, (simple or branched distally, glandular-viscid or glabrate). Flowers heterostylous; hypanthium free from ovary except at base, yellow-green to pinkish; sepals 5, yellow-green to pinkish; petals 5, white, veins prominently colored, (spatulate to elliptic, glabrous); nectary tissue not visible; stamens 10; filaments subulate, (alternate ones surpassing sepals); ovary superior, 2-locular, carpels connate to middle; placentation axile (appearing marginal); styles 2; stigmas 2. Capsules folliclelike, 2-beaked. Seeds brownish, irregular in outline with pinched, curved base, reticulate with longitudinal wings or ridges. x = 7.

Distribution

Calif., nw Mexico.

Discussion

Species 3 (3 in the flora).

Jepsonia is characterized by heterostylous flowers that are produced in the autumn after summer drought; some flowers have long styles and short stamens; others have short styles and long stamens. The floral differences associated with heterostyly within populations in this genus are part of an incompatibility mechanism that prevents self-fertilization. Leaves appear after flowering and persist through the winter if moisture is available. Rarely, leaves and flowers are present simultaneously. All three species of Jepsonia also produce a secondary taproot each year. This structure begins to grow after seasonal rains and shrivels before flowering begins. It apparently acts as a contractile root. The three species in this genus are narrow allopatric endemics.

Key

1 Caudices unbranched, ovoid to spheric; leaves 1(-3); inflorescences 1-5(-10)-flowered; hypanthia 2+ times sepals; sw California, n Baja California. Jepsonia parryi
1 Caudices branched, ovoid or flat; leaves 2-3; inflorescences (3-)4-17(-25)-flowered; hypanthia ± equaling or to 1.5 times sepals; Sierra Nevada foothills or Channel Islands > 2
2 Peduncles pink or reddish, branched near middle; petals withering; pollen bluish or cream; seeds light brown. Jepsonia heterandra
2 Peduncles greenish or olive, branched distally; petals persistent; pollen yellowish; seeds dark brown. Jepsonia malvifolia