Howell's Mariposa Lily

Calochortus howellii is known only from the Illinois River valley, Josephine County.

Stems slender, not branching or rarely branching in axil of cauline leaf, straight, 2–4 dm. Leaves: basal persistent, 20–35 cm; blade gradually tapering distally, adaxially pubescent. Inflorescences subumbellate, 1–3-flowered; bracts 2, subopposite, linear to narrowly lanceolate, attenuate, 1–3 cm. Flowers erect; perianth open, campanulate; sepals shorter than petals, ovate-acuminate, glabrous; petals yellowish white, with purplish hairs toward base, broadly obovate, cuneate, inconspicuously fringed laterally, sparingly short-hairy adaxially, apex rounded; glands transversely oblong, slightly depressed, densely covered with short, distally branching hairs, the bases of which unite at lower margin to form inconspicuous, discontinuous membranes; filaments shorter than anthers; anthers oblong-lanceolate, apex acute to short-apiculate. Capsules erect, 3-winged, ellipsoid, ca. 2 cm, base and apex acute. Seeds light-colored, irregular. 2n = 20.

Oreg.

Flowering late spring--mid summer.

Dry, rocky, serpentine soils; 300--500m.

Calochortus howellii, or Howell's mariposa lily, is a rare North American species of flowering plants in the lily family, found only in Josephine and Curry Counties in south-western Oregon.

Calochortus howellii is a bulb-forming perennial with straight stems up to 40 cm tall. Petals are white or pale yellow with purple hairs on the petals. It grows on serpentine outcrops at lower or middle elevations.