MANUAL OF NATUEAL HISTORY. 491 



seeds numerous, winged ; radicle superior. 

 Yield Liquid-Storax. (Altingiacece, Lindl.) 



5. Family. — Birches (Betulacess). Trees or shrubs ; 



leaves alternate, stipulate ; flowers amenta- 

 ceous, with bracts, which are at times verti- 

 cdllate ; stamens distinct, opposite ; anthers 

 2-celled ; ovary 2-celled ; ovule solitary, 

 pendulous, anatropal ; style single or ; 

 stigmas two ; fruit membranous, indehiscent, 

 forming a kind of cone ; seeds pendulous ; 

 albumen none ; radicle superior. Natives of 

 temperate, arctic, and antarctic regions. 

 Comprehend the species of Birch and of 

 Alder. 



6. Family. — Beefwoods (Casuarinacese). Trees, 



branching, weeping; leaves 0, replaced by 

 membranous, toothed sheaths ; flowers 

 bracteate ; male flowers in spikes, female 

 flowers in dense heads ; stamen one ; anther 

 2-celled ; ovary 1 -celled ; ovules one, ob- 

 liquely-ascending, or two side by side ; styles 

 two ; fruit of winged achsenia, collected into 

 a cone ; seed erect ; radicle superior. Natives 

 of Australasia. 



GYMNOGENS. 



Gymnogens, called also Gymnosperms, constitute 

 a small Class, in many respects closely allied to the 

 one last under consideration. Their seeds have two 



