Cusickiella

Rollins

J. Jap. Bot. 63: 68. 1988.

Etymology: For William C. Cusick, 1842–1922, Oregon plant collector
Treatment appears in FNA Volume 7. Treatment on page 412. Mentioned on page 236, 238, 240, 413.

Perennials; (cespitose or pulvinate, taprooted, caudex much-branched, woody, with persistent leaf remains); scapose or subscapose; glabrous or pubescent, trichomes simple, often mixed with stalked, forked, or subdendritic ones. Stems erect, unbranched. Leaves basal and sometimes cauline; sessile; basal (terminating caudex branches, thickened at base, persistent, erect), rosulate, blade margins entire; cauline (absent or few as bracts), blade (base not auriculate), margins entire. Racemes (corymbose, proximal flowers sometimes bracteate), elongated in fruit. Fruiting pedicels divaricate or ascending, slender. Flowers: sepals (erect to ascending), oblong; petals white or yellowish, spatulate or oblanceolate, (slightly longer than sepals, base attenuate to short claw); stamens slightly tetradynamous; filaments dilated basally; anthers ovate; nectar glands: lateral annular, median glands confluent with lateral. Fruits sessile or minutely stipitate, ovoid or ellipsoid, not torulose, terete or 4-angled, (thick and leathery); valves each with prominent or obscure midvein, (sometimes keeled), puberulent or glabrous; replum rounded; septum complete; ovules 4 per ovary; stigma capitate. Seeds aseriate, plump, not winged, ovoid to oblong; seed coat (smooth), not mucilaginous when wetted; cotyledons incumbent or obliquely so.

Distribution

w United States.

Discussion

Species 2 (2 in the flora).

Species of Cusickiella superficially resemble those of Draba, but the two genera are clearly unrelated. Cusickiella is easily distinguished from Draba by having incumbent cotyledons and four seeds per fruit, whereas Draba has accumbent cotyledons and more seeds per fruit.

Selected References

None.

Key

1 Racemes ebracteate; fruit valves rounded on back, each with obscure midvein; leaf blades (0.3-)0.5-1.2(-1.4) cm, trichomes on surfaces not setiform; petals white. Cusickiella douglasii
1 Racemes bracteate basally; fruit valves keeled on back, each with prominent midvein; leaf blades 0.2-0.5 cm, trichomes on surfaces setiform; petals pale yellow. Cusickiella quadricostata