corylus CORYLACE.E 613 



BETULA 



small bractlets which become much enlarged and involucrate 

 in fruit. Ovary imperfectly 2- celled, with 2 pendulous anatro- 

 pous ovules. Seed solitary. 



1 CORYLUS L. Sp. 998. (Hazel-nut.) 



Shrubs or small trees with broad thin leaves that are plicate in 

 the bud and small flowers that appear before the leaves ; the sta- 

 minate in drooping cylindrical aments, from lateral buds, without 

 calyx but subtended by a scaly bract, consisting of 4 stamens 

 with forked filaments, each fork bearing one cell of an anther, the 

 undivided portion adnate to the bract. Pistillate flowers several 

 in a scaly bud, 2 to each scale, each with a pair of bractlets that 

 enlarge and in fruit more or less envelope the nut : calyx minute, 

 adnate to the ovary, without limb. Style short: stigmas elonga- 

 ted. Nut oblong or ovoid, large and. bony. 



C. rostrata Ait. Hort. Kew. iii, 364. A shrub 3-8 feet high, with 

 pubescent branchlets and smooth bark: leaves ovate or narrowly oval, acu- 

 minate, cordate or obtuse at base, incised-serrate and serrulate, glabrous 

 or with some scattered appressed hairs above, sparingly pubescent, at least 

 on the veins beneath, 2)^-4 inches long, on petioles 2-4 lines long: involu- 

 cral bracts bristly hairy, united to the summit and prolonged into a tubular 

 beak about twice as long as the nut, laciniate at the summit: nut ovoid, 

 scarcely compressed, striate, 5-7 lines high. In thickets, Oregon to Brit. 

 Columbia, the Eastern States and Nova Scotia. 



€• Californica Rose. A shrub or small tree 4-30 feet high with pubes- 

 cent branchlets : leaves orbicular to obovate, 1-4 inches broad, often shortly 

 acuminate, obscurely 6-10-lobed, sharply serrate, on petioles 5-12 lines 

 long, mostly subcordate at base, sparsely pubescent above, soft-puVescen 

 on the veins beneath : involucre united to the summit, prolonged into a 

 broad tubular beak about twice as long as the nut or less, setose-hispid 

 below with short brittle hairs, erose to lacerate at the summit : nut ovoid 

 5-8 lines high. Common on low hillsides and in forests, Brit. Columbia to 

 California. 



Order XC BETULACE^ Agardh Apho. 208 in part. 



Trees or shrubs with deciduous alternate leaves, mo^ly cadu- 

 cous stipules and small moncecious flowers, the staminatein long 

 aments, the pistillate in shorter cone-like aments with thickened 

 and rigid scales. Staminate flowers 3-6 together in the axil of 

 each bract, consisting of a membranous calyx and 2-4 stamens 

 inserted on the receptacle, with distinct filaments and 2-celled 

 anthers. Pistillate aments spike-like or capitate, its flowers with 

 or without a calyx adnate to the 2-celled ovary which is crowned 

 with 2 sessile filiform stigmas and becomes a winged or angled 

 nutlet. Seed anatropous, pendulous, without albumen. Cotyle- 

 dons flat, foliaceous in germination. 



1 Betula Bracts 3-lobed, becoming coriaceous, deciduous: stamens 2, 

 with bifurcate filaments and separate anther-cells: nutlets broadly 

 winged. 



2 Alnus Bracts entire, becoming woody, persistent : stamens 4; anther- 



cells contiguous. 



