22 



Betulaceae. 



Ostrya. Hop Hornbeam. 

 (Family Betulaceae). 



Rather deliquescent trees with 

 scaly bark: deciduous. Twigs slen- 

 der, zig-zag, terete: pith small, 

 roundish, continuous, pale. Buds 

 solitary, or exceptionally super- 

 posed, sessile, ovoid, oblique, with 

 half-a-dozen spirally placed striate 

 scales, the end-bud lacking. Leaf- 

 scars alternate, 2-ranked, some- 

 what raised, crescent-shaped or 

 half-elliptical, small: bundle- 

 traces 3: stipule-scars unequal, 

 elongated. Catkins often present. 

 Winter-character references: 

 0. carpinifolia. Bosemann, 70; 

 Schneider, f. 163; Willkomm, 27, 

 f. 30. 0. virginiana. Blakeslee 

 & Jarvis, 332, 410, pi.; Brendel, 

 pi. 2; Hitchcock (1), 3, (2), 18; 

 Otis, 80; Shirasawa, 265, pi. 9. 

 A suggestive illustrated study 

 of the structure of buds as revealed in their unfolding in the 

 spring, in which Ostrya figures, is published by Hitchcock 

 in volume 6 of the Transactions of the Academy of Science 

 of St. Louis. One of many publications on buds superposed 

 above the leaves or leaf-scars is by Damaskinos and Bourgeois 

 in volume 5 of the Bulletin de la Societe Botanique de France: 

 in it, reference is made to Ostrya virginiana. 

 Scales of staminate catkins long-mucronate: nutlets glabrate, 

 fusiform. (1). O. virginiana. 



Scales blunt or abruptly short-pointed: nutlets pubescent 

 above, ovoid. (European hornbeam). (2). O. carpinifolia. 



