Resembling no. 1, but lower, often only 1 dm at first anthesis, becoming diffusely branched and to 3(-4) dm, with widely spreading branches and branchlets, the central axis often obscured; upper lf-surface more densely stellate than in no. 1 [Helianthemum canadense (L.) Michx.] (but less densely so than the lower surface) and often with fewer or no long hairs; some fls transitional between the early, open ones and the later, cleistogamous ones, which are typically solitary or paired at the tips and forks of the branches; fr of open fls 4-7 mm, with 16-50 seeds, of cleistogamous ones 3-4.5 mm, with 8-14 seeds. Dry, sandy soil and barrens; Mass. to L.I., blooming earlier than the other spp.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.