20 
BETULACEAE. 
Corytus. Hazel. Filbert. 
(Family Betulaceae). 
Shrubs: deciduous. Twigs mod- 
erate or rather slender, zig-zag, 
round: pith somewhat 3-sided, 
continuous, pale. Buds solitary, 
obliquely sessile, round or ovoid 
and obtuse with some 4-6 exposed 
scales, or early developing into 
ashen catkins, the end-bud lack- 
ing. Leaf-scars alternate, 2- 
ranked, half-round or triangular, 
somewhat raised, rather small: 
bundle-traces 3, or multiplied and 
finally obscure: stipule-scars elon- 
gated. 
Winter-character references: — 
C. americana. Brendel, pl. 2; Hitch- 
cock, (3), 18; Foerste, Bull. Torr. 
Bot. Cl. 20: 164, f.; Schneider, f. 
165.—C. Avellana. Bosemann, 68; 
Fant, 12, f. 3; Schneider, f. 164; 
Ward, 1:185. f. 92; Willkomm, 4, 
25, f. 26; Zuccarini, 5, pl. 3.—C. Colurna. Schneider, f. 164; 
Willkomm, 8, 9, 26, f. 28.—C. heterophylla. Shirasawa, 263, pl. 
8.—C. maxima. Bosemann, 68; Schneider, f. 164; Willkomm, 
26, f. 27.—C. rostrata. Schneider, f. 165; Shirasawa, 264, pl. 8. 
1. 
2. 
3. 
Buds glabrescent but with ciliate scales. 2. 
Buds gray-pubescent. 3. 
Buds small (scarcely 4 mm.). ( 1). C. Avellana. 
Buds large (6 mm. long): twigs olive. (2). C. pontica. 
Outer scales elongated, quickly falling. (3). C. rostrata. 
Seales persistent, the lower short. 4. 
. Buds rather small (4 mm.): native. (4). C. americana. 
Buds larger (often 5 mm. long). (5). C. maxima. 
