petioles. Catalpa (p. 870). Leaves linear to linear-lanceolate, short-stalked or sessile (_sometimes alternate_). Chilopsis (p. 869). _cc_ Leaves with persistent stipules, entire. Leaves oval or ovate; winter-buds resinous, the terminal up to ½′ in length. Pinckneya (p. 876). Leaves ovate to lanceolate; winter-buds minute. Cephalanthus (p. 878). _aa_ Leaves palmately lobed. Acer (p. 681). 2. Leaves Compound. _a_ Leaves persistent, with stipules. Leaves equally pinnate; leaflets entire. Guaiacum (p. 630). Leaves unequally pinnately parted into 3—8 linear-lanceolate segments (_sometimes entire_). Lyonothamnus (p. 378). Leaves trifoliate. Leaflets stalked. Amyris (p. 640). Leaflets sessile. Helietta (p. 637). _aa_ Leaves deciduous. Leaves unequally pinnate or trifoliate. Leaflets crenate-serrate or entire, the veins arching within the margins; stipules wanting; winter-buds with several opposite scales. Fraxinus (p. 833). Leaflets sharply or incisely serrate, the primary veins extending to the teeth. Leaflets 3—7, incisely serrate; stipules present; winter-buds with 1 pair of obtuse outer scales. Acer Negundo (p. 699). Leaflets 5—9, sharply serrate; stipules present; winter-buds with many opposite acute scales; pith thick. Sambucus (p. 882). Leaves digitate, with 5—7, sharply serrate leaflets; terminal buds large. Æsculus (p. 702). B. LEAVES ALTERNATE. 1. Leaves Simple. (2, see p. xxiv). * Leaves persistent. (** see p. xxii).