180 MANUAL OF BOTANY 



1— 2, naked, pointed by a stjde-like process. Seed succulent ; 

 embryo dicotyledonous, in the axis of fleshy albumen. 



Distribution and Numbers. — These plants occur in both 

 tropical and temperate regions. There are 3 genera— Ephedra, 

 Linit. ; Welwitschia, Beiclib. ; and Gnetum, Linn. ; and about 

 30 species. 



Properties and Uses. — Unimportant. The seeds and leaves 

 of several species are eaten. Some Ejihedras are astringent. 



Order 4. Cycadaceje, theCycas Order. — Character. — Small 

 Palm-like unbranched or occasionally dichotomous trees or 

 shrubs, with their surface marked by the scars of fallen leaves. 

 Leaves clustered at the summit, pinnate, parallel-veined, hard 

 and woody ; leaflets sometimes circinate in vernation. Floivers 

 quite naked, unisexual, dioecious. Male fioivers in cones, con- 

 sisting of scales, from the under surface of which 1- celled 

 pollen sacs arise. Female flowers consisting of naked ovules 

 placed on the margins of altered leaves, or of ovules arising from 

 the base of flat scales or from the under surface of peltate ones. 

 Seeds hard or succulent, with 1 or several embryos contained in 

 fleshy or mealy albumen. 



Distribution and Numbers. — Natives principally of the tem- 

 perate and tropical parts of America and Asia ; and occasionally 

 of the Cape of Good Hope, Madagascar, and Australia. Illus- 

 trative Genera : — Cycas, Linn. ; Zamia, Lindl, There are 

 about 50 species. 



Properties and Uses. — The stems and seeds of the plants of 

 this order yield mucilage and starch. 



Artificial Analysis of the Orders in the Gymnospekm^. 



1. Stem jointed, branched Gnetacecp. 



2. Stem not jointed. 



Branched. Leaves simple. 



Carpels ccllected in cones .... ConifercB. 



Seed solitary, usually surrounded by a suc- 

 culent coat Taxacece. 



Not branched ordichotomoiis. Leaves pinnate Cycadacece. 



