II. Staminate flower without bractlets ; pistillate ament spike-like; 

 nuts small, subtended or enclosed by an involucre, 



a. Fruiting braetlet flat, 2 cleft, foliaceous. ....... QarpimiS. 



b. Fruiting braetlet bladder-like, entire or 3 lobed. 



1. Fruiting braetlet entire Ostrya. 



2. Fruiting braetlet 3 lobed Ostryopsis. 



B. Staminate flowers 3-6 in the axils of the scales, with c^alyx; 

 pistillate flower without calyx, the ament becoming a coriaceous 

 or woody strobile; nuts without involucre, more or less winged. 



I. Pistillate ament solitary, the scales deciduous; stamens 2; 

 winter buds scaly ; strobile coriaceous Beiula. 



II. Pistillate ament racemose, the scales becoming thick, woody 

 and persistent; stamens-4; winter buds without scales. .Alaus. 



OSTKYA . , 



Small trees. Buds scaly, pointed. The staminate flower buds in. 

 terminal, naked catkins; the- pistillate flower buds, enclosed in axillary 

 scaly buds. Leaves deciduous, doubly serrate, stalked, pinnately veined', 

 stipules oblong or lanceolate, deciduous. Flowers monoecious, apetalous; 

 the staminate clustered, in pendulous, terminal catkins; pistillate catkins 

 from axillary buds, erect, each scale bearing 2 ovaries, calyx adnate to the 

 o\»ary; ovary inferior, 2 celled, 1 ovuled; each pistil enclosed in a hairy 

 sac-like involucre formed by the union of the bracts and the bracteoles'. 

 Fruit a stalked strobile composed of the imbricated, inflated, bladder-like 

 involucre enclosing a nutlet. Nutlet ovoid, compressed, sessile, crowned 

 by the remnant of the calyx, conspicuously ribbed. Seeds solitary. 



4 species in N. America, Europe, and Asia. 



The species are so closely allied that botanists are disposed to regard 

 them as geographical variants of the same species. The genus is easily 

 recognized by the cone or hop-like .fruits composed of flattish, i-nflateo!,, 

 membranous, bladder-like bracts each enclosing a small, bony nutlet. 

 The tree is slow growing and never attains a large size, 1 and the hard, close- 

 grained wood has little commercial 'value,, although locally useful/ The 

 se eds. usually do riot germinate until the second year, ■).. i 



