182 RHAMNACE^. 



Fruit three-lobed, three-celled, tricoccoiis, girt at the base 

 by the persistent and commonly adnate base of the calyx, at 

 first drupaceous, but the usually thin sarcocarp soon dries up ; 

 the endocarp dehiscent into three crustaceous or cartilagi- 

 nous at length two-valved cocci. Seed solitary in each 

 cell, erect, with a broad basilar caruncle at the hilum, obo- 

 vate-lenticular, with a smooth crustaceous testa, not sulcate ; 

 the raphe ventral. Embryo in the axis of fleshy albumen, of 

 nearly its length and width : cotyledons oval or obovate, 

 thin and flat : radicle very short, inferior. 



Shrubs, or suffruticose plants, sometimes spinescent ; with 

 alternate (rarely opposite) usually serrulate leaves. Stipules 

 minute and caducous. Flowers perfect, small, but usually 

 handsome, being collected in umbel-like fascicles, which are 

 aggregated into dense thyrsoid cymes or panicles at the ex- 

 tremity of the branches ; the pedicels as well as the calyx and 

 corolla usually colored, white, blue, or sometimes yellowish. 



Etymology. Kedvcudos, a name applied by Theophraslus to some prickly 

 plant, and transferred by Linnseus to this genus, for no assigned reason. 



Properties. The root of C. Americanus is dark red, and yields a cinna- 

 mon-colored dye. It possesses considerable astringency, as do the leaves, 

 which were used during the American Revolution as a substitute for tea. 



Geographical Distribution. This pretty large genus, as now limited, 

 is entirely North American. Five species are natives of the United States, 

 the rest belong to Oregon, Northern Mexico, and especially to California. 



PLATE 169. Ceanothus Americanus, Z/n^.,- — a flowering branch. 

 1. Diagram of the flower. 2. A flower, magnified. 



3. Vertical section of a flower, more magnified. 



4. Side view of a petal and a stamen, still more magnified. 



5. A magnified stamen, seen from the inner side. 



6. An ovule, magnified. 



7. A fruit, magnified, showing the thin and dry sarcocarp. 



8. The same more magnified, dehiscent into three cocci and separating 



from the persistent base of the calyx. 



9. Vertical section of a seed, at right angles to the cotyledons, magnified. 



10. A magnified seed transversely divided, the inner side towards the eye. 



11. Vertical section of the seed parallel with the cotyledons, displaying 



the embryo. 



