Frangula purshiana (DC.) A.Gray ex E.Cooper
cascara sagrada
Large shrub or small tree (2)-6-7 m tall. Buds, young shoots and very young lvs with ferruginous tomentum. Petiole 1-2.5 cm long, tomentose. Lamina 5-13.5 × 3-7 cm, broad-elliptic or elliptic-obovate, ± hairy, densely hairy on the raised 12-16 pairs of veins beneath, subentire or crenulate-serrulate; base rounded or subcordate; apex mostly shortly cuspidate. Peduncles 5-35 mm long, ferruginous-tomentose; pedicels similar but shorter. Bracts to 1 mm long, subulate. Calyx c. 4 mm long, ferruginous-tomentose outside; lobes 1.3-2 mm long, triangular. Petals included, whitish; < calyx lobes; limb wider than long. Style c. 1 mm long; ovary glabrous. Fr. turbinate, black, 3-seeded.
S.: Golden Downs Forest (near Nelson), cultivation escape.
W. North America 1983
Forming an understorey in a birch plantation along c. 0.5 km of roadside.
FL Jun-Mar.
F. purshiana is only rarely cultivated in N.Z. It could be confused with the European F. alnus Miller, alder buckthorn, which is occasionally grown, but in this sp. the fls are in glabrous, sessile fascicles. F. purshiana has been previously known as Rhamnus purshiana in N.Z.