

BirruLA.] CTJPULIFERJE. 365 



Calyx adnate to the ovary, or 0. Ovary inferior, after fertilization more 

 or less completely 2-3- (rarely 4-6-) celled ; styles as many, stigmatose 

 above and within ; ovules 1, or 2 collateral, erect or pendulous, anatro- 

 pous. Fruit indehiscent, 1- rarely 2-seeded, seated on or enclosed in the 

 hardened or accrescent bracts. Seed large, testa thin often adherent to the 

 pericarp, albumen ; cotyledons thick, fleshy or farinaceous, often grooved 

 or folded ; radicle short, superior. — Distrib. N. hemisphere, from 

 N. Africa, N. India, the Malay Is. and Darien northwards, Mts. of South 

 Australia, N. Zealand, Chili ; genera 10 ; species about 400. —Affinities. 

 With Juglandeai. — Properties. Yield tannin, many good woods, and 

 esculent embryos. 



Tribe I. BETULE'iE. Male fl. Spikes pendulous. Sepals 4 or fewer. Stamens 

 %A. Female fl. 2-3 under each side of a catkin-like spike. Perianth 0. 

 Ovary 2-celled, cells 1-ovuled ; styles 2. Fruit small, compressed, covered 

 by the scales of the spike. 



Stamens 2 ; scales of female spike thin, deciduous, 3-fid 1. Betula. 



Stamens 4 ; scales of female spike persistent, woody 2. Alnus, 



Tribe II. QUERCINE'-ffi, MaleA. Calyx 4-10-lobed or -partite. Filaments 

 simple ; anther-cells connate. Female fl. 1-3 in an involucre of many 

 bracteoles which enlarges in fruit. Ovary 3-7-celled; ovules 2 in each 

 cell. Fruit seated in a cupular involucre. 



Male catkins slender. Styles 3, short 3. Quercus. 



Male catkins globose. Styles 3, filiform 4. Fagus. 



Tribe III. CORYLE'JE. MaleA. Catkins pendulous. Perianth 0. Stamens 

 included between 2 bracteoles ; anther-cells separate or connate, hairy at 

 the tip. Female fl. in pairs ; bracts enlarging in fruit. Ovary imperfectly 

 2-celled ; ovules 2, pendulous from one placenta only. Fruit enclosed in 

 the coriaceous bracts. 



Female spike minute, with few brown scales 5. Corylus. 



Female spike large, with many leafy scales 6. Carpinus. 



1. BE'TULA, Tournef. Birch. 



Trees or shrubs. • Flowers monoecious. — Male catkin. Scales peltate, 

 with 3-bibracteolate flowers. Sepals 1-4. Stamens 2, filaments forked, 

 separating the anther-cells. — Female. Bracts imbricate, usually 3-lobed, 

 2-3-fld. ; bracteoles 0. Perianth 0. Ovary compressed, 2-celled ; styles 

 2, slender, stigmas terminal. Ovules 1 in each cell. Fruit lenticular, 

 winged or margined, 1-seeded. Cotyledons flat. — Distrib. !N\ temp, and 

 Arctic regions, Mexico to Peru ; species about 25, — Etym. The Latin 

 name. 



1. B. alba, L. ; a tree, leaves long-petioled deltoid rhomboid or ovate 

 acute doubly serrate, fruit broadly winged. 

 Woods and copses, N. to Orkney ; ascends to 2,500 ft. in the Highlands ; 



Ireland; Channel Islands; fl. April-May.— A short-lived tree, 40-50 rarely 



