NATTTKAL ORDEES. 



285 



Fi'jj. 206. 



Sub-order Artocakpe^, the Bread-fruit Tribe. — Seed erect or 

 pendulous, albuminous ; embryo straight; juice milky. 



Genera, — Artocarpus. 



Fig. 207, a, staminate flower of Urtica urens (oettle) expanded ; b, perianth 

 with 4 divisions; s, stamens thrown back by the elasticity of the filaments, with 

 the anthers burst ; p, pistillate flower, the two outer segments of the perianth very 

 small; o, 1 -celled ovary ; st, sessile stigma; c, pistil cut vertically to show the di- 

 rection of the erect ovule ; /, seed cut perpendicularly to the cotyledons. 



Sub-class II.- 



-Gymnospekmous, Exogenous Plants. 



529. CoNiFEKiE, the Fir Tribe. — Trees or shrubs with branch- 

 ed trunks, abounding in resin, the wood marked with circular 

 disks. Leaves linear, lanceolate, or acerose, usually evergreen. 

 Flowers monoecious or dioecious, commonly amentaceous. In 

 the staminate flowers each floret consists of one or more sta 

 mens destitute of calyx or corolla, and arranged upon a com- 

 mon rachis forming a loose ament. Pistillate flowers in 

 cones. Ovary flat and scale-like ; ovules in pairs, adherent to 

 the base of the ovary. Fruity a cone formed of scale-shaped 

 ovaries enlarged and indurated. Integument of the seed crusta- 

 ceous ; embryo in fleshy, oily albumen ; cotyledons 2, or many. 



a. Properties : important timber-trees, furnishing valuable resinous products. 

 Genera. — 1. Abiet^ — Pinus. 2. Cupress.e — Juniperus, Thuja, Cupressus, 3. Tax,« 

 — Taxus. 



530. Cycadace^, the Cycas Tribe. — Small trees or shrubs 

 with simple, cylindrical trunks. Leaves pinnate, circinate in 

 vernation. Flowers dioecious, terminal, destitute of calyx or 

 corolla. Staminate flowers in a strobile or cone. Pistillate 

 flowers also in strobiles, or occupying contracted and partly 

 metamorphosed leaves. Ovules solitary, naked. Seeds hard 

 or spongy-coated nuts. 



Genera. — Cycas, Zamia. 



