Hydrangea arborescens L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Straggling shrub 1–3 m; lvs ovate-oblong to broadly round-ovate, acuminate, serrate, subcordate to acute at base, glabrous above; infl flat-topped or broadly convex, 5–10 cm wide, fertile throughout or with some marginal fls sterile or rarely wholly sterile (the wholly sterile form often cult.); pet 5, white, 3 mm; stamens 10; ovary inferior, with 2(3) carpels; sep of the sterile fls (3)4, subrotund, nearly 1 cm, white, reticulate-veined; seeds elliptic, with blunt ends; 2n=36. Dry or moist, often rocky woods and hillsides; s. N.Y. to O., Mo., and Okla., s. to Ga., La., and Ark. June, July. The widespread var. arborescens has the lvs glabrous or with only a few scattered hairs along the midrib beneath. The well marked var. discolor Ser. (var. deamii) occurring from c. Ind. and Ill. to N.C., Ga., and Okla., has the lvs ± densely pubescent beneath with minutely tuberculate hairs. The var. discolor might perhaps equally well be treated as a distinct, closely allied species, H. cinerea Small.