Plants 2.7-6 dm; rhizomes short, thick. Cauline leaves 3-4; blade dark green, oblong to obovate-elliptic, 18-30 × 4.5-8 cm. Inflorescences in terminal clusters, 10-25(-30)-flowered; bract 1, foliaceous. Flowers: tepals white to greenish white, often spotted purplish brown or green distally, ovoid-obovate, 5.5-8 × 2.7-4 mm; filaments 5.5-7 mm; anthers short-oblong, 3.5-5.5 mm. Berries black, globose to ellipsoid, 2-4-seeded, 6-8 mm. Seeds 3-4 mm. 2n = 28. Flowering early May--late Jun. Rich cove hardwood forests; 200--1000 m; Ga., Ky., Md., N.Y., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va. Clintonia umbellulata and C. borealis are allopatric in the southern Appalachians (P. P. Gunther 1972). A putative hybrid between the two, C. allegheniensis Harned (J. E. Harned 1931) is not recognized here and is regarded as a mere fruit-color variant of C. umbellulata (F. H. Utech 1973). Isozyme evidence supports this conclusion (M. T. Blain 1997).
Much like no. 1 [Clintonia borealis (Aiton) Raf.]; fls mostly 10-24, ±erect, the tep 8-10 mm, greenish-white, spotted with purplish-brown; ovules 2 per locule; fr black, 6-8 mm thick; 2n=28. Mt. woods.; c. N.Y. and e. O. to N.C., Tenn., and n. Ga. May, June. (Xeniatrum u.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.