Leaves deciduous, broad-elliptic, obtuse or bluntly pointed at apex, rounded or slightly cordate at base, finely serrate, or often nearly entire, with undulate margins, thin, villose with short hairs on the lower surface and on the veins above, 1½′—7′ long, 1½′—2′ wide, conspicuously netted-veined, with a broad and prominent midrib and primary veins; turning pale yellow late in the autumn before falling; petioles stout, often pubescent, ½′—1′ in length; stipules membranaceous, acuminate. Flowers on slender pubescent pedicels ¼′—1′ long, in axillary cymes on slender pubescent peduncles ½′—1′ in length on shoots of the year; calyx nearly campanulate, with 5 spreading acuminate lobes; petals 5, minute, ovate, deeply notched at apex, and folded round the short stamens; stigma 2 or 3-lobed. Fruit globose or broad-obovoid, black, ⅓′—½′ in diameter, slightly or not at all lobed, with thin rather juicy flesh, and 2 or 3 obovoid nutlets usually ⅓′ long, rounded on the back, flattened on the inner surface, with 2 bony tooth-like enlargements at base, 1 on each side of the large scar of the hilum, and a thin gray or pale yellow-green shell; seeds obtuse at apex, rounded on the back, seed-coat thin and papery, yellow-brown on the outer surface, bright orange color on the inner surface like the cotyledons.
A tree, 35°—40° high, with a slender trunk often 18′—20′ in diameter, separating 10°—15° from the ground into numerous stout upright or sometimes nearly horizontal branches, and slender branchlets coated at first with fine soft pubescence, pale yellow-green or reddish brown, and pubescent, glabrous, or covered with scattered hairs in their second season and then marked by the elevated oval horizontal leaf-scars; often shrubby and occasionally prostrate. Winter-buds naked, hoary-tomentose. Bark of the trunk rarely more than ¼′ thick, dark brown to light brown or gray tinged with red, broken on the surface into short thin scales. Wood light, soft, not strong, brown tinged with red, with thin lighter colored sapwood. The bark possesses the drastic properties peculiar to that of other species of the genus, and is a popular domestic remedy in Oregon and California, and under the name of Cascara Sagrada has been admitted into the American materia medica.
Distribution. Rich bottom-lands and the sides of cañons, usually in coniferous forests; shores of Puget Sound eastward along the mountain ranges of northern Washington to the Bitter Root Mountains of Idaho and the shores of Flat Head Lake, Montana, and southward to central California; Arizona, southern slope of the Grand Cañon of the Colorado River, Coconino County (A. Rehder), Cave Creek Cañon, Chiricahua Mountains, Cochise County (J. W. Toumey).
Occasionally cultivated in the gardens of western Europe and of the eastern United States.
5. CEANOTHUS L.
Small trees or shrubs, with slender terete branches, without a terminal bud, and small scaly axillary buds. Leaves petiolate, 3-ribbed from the base, or pinnately veined, persistent in the arborescent species. Flowers on colored pedicels, in umbellate fascicles collected in dense or prolonged terminal or axillary thyrsoid cymes or panicles, blue or white; calyx colored, with a turbinate or hemispheric tube and 5 triangular membranaceous petaloid lobes; disk fleshy, thickened above; petals 5, inserted under the margin of the disk, unguiculate, wide-spreading, deciduous, the long claw infolded round the stamens; stamens 5, inserted with and opposite the petals, persistent, filaments spreading; ovary partly immersed in and more or less adnate to the disk, 3-celled, sometimes 3-angled, the angles often surmounted by a fleshy gland persistent on the fruit; styles short, united below; stigmas 3-lobed with spreading lobes; ovule erect from the base of the cell. Fruit 3-lobed, subglobose, with a thin outer coat, soon becoming dry, and separating into 3 crustaceous or cartilaginous longitudinally 2-valved nutlets. Seeds erect, obovoid, lenticellate, with a broad basal excrescence surrounding the hilum; seed-coat thin, crustaceous; albumen fleshy; embryo axile; cotyledons oval or obovate.
Ceanothus is confined to the temperate and warmer regions of North America, with about thirty species, mostly belonging to California. The leaves, bark, and roots are astringent and tonic. Of the species of the United States three are small trees.
The generic name is from κεάνωθος, the classical name of some spiny plant.