_a_ Leaves deeply 3—5-lobed, ⅓′—½′ long, with linear lobes, hoary tomentose below. Cowania (p. 549). _aa_ Leaves palmately lobed. Leaves stellate-pubescent, about 1½′ in diameter, with stipules. Fremontia (p. 749). Leaves glabrous, 1°—2° in diameter, without stipules. Carica (p. 755). _aaa_ Leaves not lobed or pinnately lobed. _b_ Branches spinescent. Leaves clustered at the end of the branches, at least 2′—3′ long. Bucida (p. 765). Leaves fascicled on lateral branchlets, obtuse or emarginate, pale and glabrous beneath. Bumelia angustifolia (p. 816). Leaves scattered. Leaves generally obovate, mucronate, not more than ½′—1′ long, glabrous and green or brownish tomentulose beneath. Condalia (p. 719). Leaves elliptic-ovate to oblong, obtuse or emarginate, glabrous, 1—2 cm. long. Ximenia (p. 337). _bb_ Branches not spinescent. _c_ Leaves serrate, or lobed (_in some species of Quercus_). (_cc_, see p. xxii). _d_ Juice watery. (_dd_, see p. xxii). _e_ Stipules present. (_ee_, see p. xxii). _f_ Primary veins extending straight to the teeth. Leaves and branchlets glabrous or pubescent to tomentose with fascicled hairs. Leaves fulvous-tomentose beneath, repand-dentate, 3′—5′ long. Lithocarpus (p. 236). Leaves glabrous or grayish to whitish tomentose beneath, entire, lobed or dentate. Quercus sp. 21—34 (p. 268). Leaves and branchlets coated with simpled silky or woolly hairs at least while young, not more than 2½′ long. Cercocarpus (p. 550). _ff_ Primary veins arching and united within the margin. Leaves 3-nerved from the base. Ceanothus (p. 726). Leaves not 3-nerved. Leaves acute. Leaves sinuately dentate, with few spiny teeth (_rarely entire_), glabrous. Ilex opaca (p. 669). Leaves serrate. Leaves tomentose below; branchlets tomentose. Leaves narrow-lanceolate, glabrous and smooth above. Vauquelinia (p. 377).