Deciduous trees or shrubs. Twigs quite thick; pith large, continuous. Buds, especially the terminal, quite large, solitary, ovoid, sessile, with 6 or more pairs of scales. Leaf-scars opposite, large, shield-shaped or triangular; bundle-traces 3 or in 3 groups, sometimes 7 or 9; stipule-scars none. The twigs sometimes end in an inflorescence - or fruit-scar (see p. 7 )
Buds brownish, not gummy
b. Bark rough, soft and corky; ill-scented; fruit spiny
b. Bark smooth and firm, not ill-scented; fruit smooth
Buds nearly black, gummy
1. A. glabra Willd. Fetid Buckeye. Ohio Buckeye. Small tree up to about 20 m. high; bark gray, breaking into plates, exhaling an unpleasant odor; terminal bud 1. 5-1. 8 cm. long, pointed, the outer bud scales reddish-brown, finely hairy on the margins; fruit spiny. Rich woods, Pennsylvania to Nebraska, south to Alabama and Oklahoma (Fig. 202). *
2. A. octandra Marsh. Sweet Buckeye. A tree up to 25 m. high, with light brown to grayish-brown bark breaking up into numerous thin irregular scales; terminal bud 1. 5 cm. long, somewhat pointed, the outer scales reddish-brown, covered with a thin bluish bloom; fruit smooth. Rich woods, Pennsylvania to Michigan and Iowa, south to Georgia (Fig. 203).
Fig. 202. Aesculus glabra.
Fig. 203. Aesculus octandra.
Fig. 204. Aesculus hippocastanum.
3. A. hippocastanum L. Horse-Chestnut. A tree up to about 25 m. high, with large gummy varnished buds; fruit spiny. Introduced from Europe, sometimes seeding itself from cultivated trees (Fig. 204).