20 



BETULACEAE. 



CORYLUS. 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, pi. 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, pi. 3. (7. Colurna. Schneider, f. 164; 

 Willkomm, 8, 9, 26, f. 28. C. heterophylla. Shirasawa, 263, pi. 

 8. C. maxima. Bosemann, 68; Schneider, f. 164; Willkomm, 



26, f. 27. C. rostrata. Schneider, f. 165; Shirasawa, 264, pi. 8. 



1. Buds glabrescent but with ciliate scales. 2. 

 Buds gray-pubescent. 3. 



2. Buds small (scarcely 4 mm.). 



Buds large (6 mm. long): twigs olive. 



3. Outer scales elongated, quickly falling. 

 Scales persistent, the lower short. 4. 



4. Buds rather small (4 mm.): native. 

 Buds larger (often 5 mm. long). 



(1). C. Avellana. 



(2). C. pontica. 



(3). C. rostrata. 



(4). C. americana. 

 (5). C. maxima. 



