Hydran'gea arbores'cens, Hydrangea, Seven-barks, N.F. -- Saxifragaceae. The dried rhizome and roots with not more than 3 p.c. of foreign organic matter; N. America, on rocky banks near streams: .3-2.5 M. (1-8 degrees) high, stem grayish, bark exfoliates into thin layers (7), glabrous; leaves ovate, serrate, pale green beneath; flowers cymes, flat, greenish; fruit 2-celled, 2-beaked, many-seeded capsule. Rhizome, usually in pieces 3-10 Cm. (1 1/5-4') long, 3-20 Mm. (1/8-4/5') thick, yellowish-brown, wrinkled, lenticels, stem-scars above, fibrous roots beneath; fracture tough, whitish, wood radiate--pith; roots 25 Cm. (10') long, 2 Mm. (1/12') thick--no pith; inodorous; taste sweetish, acrid. Powder, yellowish-tracheae, tracheids, stone cells, numerous calcium oxalate raphides, starch grains; solvent: 60 p.c. alcohol; contains hydrangin (glucoside) 1 p.c., volatile oil, fat, resin, starch, ash 3 p.c. Diuretic, narcotic; renal and cystic calculi. Dose, gr. 15-30 (1-2 Gm.); 1. Fluidextractum Hydrangeae (60 p.c. alcohol). 2. Elixir Hydrangeae et Lithii, 40 p.c., + lithium benzoate and salicylate aa 2.6 p.c. Dose, 3j-2 (4-8 cc.).