•'J'UKhS UV TlIK NokTllKUX L^NITKD S |A PKS l-'> 



'7. Ovulary l-locular, many seeded; seeds with a tuft of 

 cottony liairs. Salicaceae. 

 a. Stamens numerous; l)racts timl)riate or entire, 

 buds with several exposed scales; pith 5- 

 angled. Populus. (64). 

 a. Stamens "J-IO; bracts entire; buds with 1 outer 

 scale. Salix. (05). 

 '.7. Ovulary 1-2 lr)cular. with 1-2 ovules in each cavity; 



seeds not with cottony hairs. ^:^8. 

 >8. Carpellate tlowers single in the axils of tiie bracts; 

 young twigs and leaves glandular dotted; buds 

 clustered at the tip of the twig. Myricaceae. 



a. Myrica. (68). 



^S. Carpellate flowers 2 or more in each bract of the 



anient: twigs and leaves not glandular dotted; 



buds not clustered at the tip of the twig. Betulaceae. 



a. I'ith :!-angled; buds stalked; leaves not 2-ranked; 



slanuMi> I. Alnus. (0<>). 



a. Pith not 8-angled; buds sessile; leaves 2-ranked. b. 



b. Staminate tlowers 3-6 in the axil of each bract, 



with a calyx; carpellate flowers without a calyx; 

 stamens 2. Betula. (59). 



b. Staminate flowers solitary in the axil of each 



bract, without a calyx; carpellate flower with a 

 calyx, c. 



c. Fruiting bract flat, 3-cleft and incised; bark 



smooth; trunk and large branches with peculiar 

 fluted or projecting ridges. Carpinus. (57). 

 c. iM-uiting bract bladder-like, closed; bark of ohk-r 

 trunks scaly and line-furrowed. Ostrya. (58). 



—39— 



;i!). I- lowers hypogynous (ovulary superior). !<•. 



• !!•. hlowers epigynous (ovulary inferior). II. 



|n. Stamens free from the corolla (or only very slightly 



united at the base) as man\- as the petals (flowers 



tetracyclic) and alternate with them. oi- twice as 



many ( pentac\clic ) or more. 11. 

 40. Stamen> united with the corolla, as many ;is the petals 



and opposite them or twice as many or more. 12 



