Internodes distinctly longer than broad; branchlets flattened, of nearly equal color on both sides; leaves eglandular. Libocedrus (p. 65). Internodes about as long as broad, often pale below, usually glandular. Branchlets flattened. Branchlets in one plane, much flattened, 1/12′—⅙′ broad. Thuya (p. 67). Branchlets slightly flattened, 1/24′—1/16′ broad. Chamæcyparis (p. 75). Branchlets terete or 4-angled. Branchlets more or less in one plane; fruit a cone. Cupressus (p. 69). Branchlets not in one plane; fruit a berry (_leaves needle-shaped, in whorls of 3 in No. 1_). Juniperus (p. 78). 2. Leaves Deciduous. Leaves in many-leafed clusters on short lateral spurs. Larix (p. 31). Leaves spreading in 2 ranks. Taxodium (p. 63). III. Leaves netted-veined, rarely scale-like or wanting. Dicotyledons. A. LEAVES OPPOSITE. (B, see p. xix). 1. Leaves Simple. (2, see p. xviii). Leaves persistent. _a_ Leaves with stipules. _b_ Leaves entire or occasionally slightly crenate or serrate. _c_ Leaves emarginate at apex, very short-stalked, 1½′—2′ long. Leaves obovate, gradually narrowed into the petiole. Gyminda (p. 678). Leaves oval to oblong, rounded or broad-cuneate (_rarely alternate_). Branchlets densely velutinous. Krugiodendron (p. 721). Branchlets slightly puberulous at first, soon glabrous. Reynosia (p. 720). _cc_ Leaves not emarginate at apex. Leaves obtuse, rarely acutish or abruptly short-pointed. Leaves elliptic, 3½′—5′ long. Rhizophora (p. 763). Leaves obovate, usually rounded at apex, ¾′—2′ long. Byrsonima (p. 632). Leaves acute to acuminate. Leaves oblong-ovate to lanceolate; branchlets glabrous. Exostema (p. 877). Leaves broad-elliptic to oblong-elliptic; branchlets villose. Guettarda (p. 879). _bb_ Leaves serrate (_often pinnate_). Lyonothamnus (p. 378). _aa_ Leaves without stipules.