Shrubs, usually with branched spines (representing modified leaves) subtending short spurs bearing fascicled foliage leaves. Wood and pith yellow. Twigs grooved, slender; pith relatively large, round, continuous. Buds rather small, solitary, sessile, ovoid, with about 6 scales. Leaf-scars alternate, small, half-round; bundle-traces 3, minute; stipule-scars none.
Fig. 98. Berberis canadensis.
Fig. 99. Berberis vulgaris.
Fig. 100. Berberis thunbergii.
Twigs finely warty, slightly angled
Twigs not warty
b. Twigs gray or buff
b. Twigs reddish-brown
1. B. canadensis Mill. American Barberry. A shrub 3-24 dm. high; twigs glabrous, slender, red-brown, warty; spines 3-parted, up to 12 mm. long; berries scarlet, oval or subglobose, 7-9 mm. long. Dry woodlands, mountains of West Virginia and Virginia to Georgia; also in Missouri; not native in Canada, despite the name (Fig. 98).
2. B. vulgaris L. European Barberry. A glabrous shrub 2-3 m.high, the branches arched and drooping at the ends, the twigs glabrous, gray or buff, strongly grooved; spines unbranched or mostly 3-parted; berries scarlet, ellipsoid. Introduced from Europe and abundantly naturalized in thickets (Fig. 99).
3. B. thunbergii DC. Japanese Barberry. Compact low-spreading, 0. 5-1. 5 m. high, with brown twigs and unbranched spines; berries ellipsoid to globose. Introduced from Asia, somewhat spreading,from cultivation (Fig. 100).