3. PACHÝSTIMA, Raf.
Flowers perfect. Sepals and petals 4. Stamens 4, on the edge of the broad disk lining the calyx-tube. Ovary free; style very short. Pod small, oblong, 2-celled, loculicidally 2-valved. Seeds 1 or 2, enclosed in a white membranaceous many-cleft aril.—Low evergreen shrubs, with smooth serrulate coriaceous opposite leaves and very small green flowers solitary or fascicled in the axils. (Derivation obscure.)
1. P. Cánbyi, Gray. Leaves linear to linear-oblong or oblong-obovate, obtuse, 3´´–1´ long; pedicels very slender, often solitary, shorter than the leaves; fruit 2´´ long.—Mountains of S. W. Va.
Order 27. RHAMNÀCEÆ. (Buckthorn Family.)
Shrubs or small trees, with simple leaves, small and regular flowers (sometimes apetalous), with the 4 or 5 perigynous stamens as many as the valvate sepals and alternate with them, accordingly opposite the petals! Drupe or pod with only one erect seed in each cell, not arilled.—Petals folded inwards in the bud, hooded or concave, inserted along with the stamens into the edge of the fleshy disk which lines the short tube of the calyx and sometimes unites it to the lower part of the 2–5-celled ovary. Ovules solitary, anatropous. Stigmas 2–5. Embryo large, with broad cotyledons, in sparing fleshy albumen.—Flowers often polygamous, sometimes diœcious. Leaves mostly alternate; stipules small or obsolete. Branches often thorny. (Slightly bitter and astringent; the fruit often mucilaginous, commonly rather nauseous or drastic.)
[*] Calyx and disk free from the ovary.
1. Berchemia. Petals sessile, entire, as long as the calyx. Drupe with thin flesh and a 2-celled bony putamen.
2. Rhamnus. Petals small, short-clawed, notched, or none. Drupe berry-like, with 2–4 separate seed-like nutlets.
[*][*] Calyx with the disk adherent to the base of the ovary.
3. Ceanothus. Petals long-clawed, hooded. Fruit dry, at length dehiscent.