GYMNOSPERMiE 



179 



in all parts of the world ; but they abound most in temperate 

 climates. There are about 250 species. 



Propertiei and Uses. — They possess very important proper- 

 ties. Many supply valuable timber, and most of the species 

 contain an oleo-resinous juice or turpentine, which is composed 

 of a volatile oil and resin. 



Order 2. Taxaoe/e, the Yew Order.— Character. — Trees or 

 shrubs, with continuous branches. Leaves usually narrow, 

 rigid, and veinless ; sometimes broad, with forked veins. 

 Flowers unisexual, naked, bracteate. Male flowers several 

 together, each with one or several stamens, which, in the latter 

 case, are united or distinct ; anthers bursting longitudinally. 

 Female flowers solitary, and consisting of a single erect naked 

 ovule, which is either terminal or placed in the axil of a bract. 

 Seed small, usually more or less surrounded by a cup-shaped 

 fleshy mass or aril, albiuninous ; embryo straight. This order 



Fig. 933. 



Fig. 934. 



Fig, 93a. Male flower o£ the 

 Common Yew (Taxns bac- 

 cata), with numerous mo- 



nacTelphous stamens. 



Fig. 934. Vertical section 

 of the seed of the same. ar. 

 Tlie succulent cup-shaped 

 ma=s which surromids the 

 seed. pi. Embryo, alb. Al- 

 bumen, ch. Chalaza. mu 

 Micropyle. 



is noiv frequently incUidcd in the ConifercB, forming the tribe 

 or sub-order Taxece or Tarinece. 



Distribution and Numbers. — Natives of the mountains of 

 tropical countries, and of temperate regions. Illustrative 

 Genera: — Taxus, Linn.; Salisburia, Smith. There are about 

 50 species. 



Properties and. Uses. — In their general properties they re- 

 semble the Coniferse. 



Order 3. Gnetace^, the Jointed Fir Order. — Character. 

 Small trees or shrubs, with usually jointed stems and branches. 

 Leaves opposite, entire, net- or parallel-veined, or sometimes 

 small and scale-like. Flowers unisexual or rarely hermaphro- 

 dite, in catkins or heads. Male flowers with a 1-leaved cahjx ; 

 anthers 2 — 3-ceUed, with porous dehiscence. Female flowers 

 naked or surrounded by 2 more or less combined scales ; ovules 



x2 



