Trees of low stature, simple trunks with the internodes undeveloped and the surface scarred with the fallen leaves which were pinnate, parallel-veined, circinate. Flowers dioecious, in cones,Order CXXIX Cycadaceae Cycades 1872 anther covering the under surface of the connective. $ Scales peltate, scale-like or leaf-like, bearing naked ovules dorsal or marginal.

Genera 7, species 46, chiefly tropical. The Cycades form the connecting link between the Exogens and the Cryptogamia.

CY'CAS revoluta, a palm-like plant, representing this order endures the winters of the far South, and is frequent in the greenhouses of the North. Its long, pinnate leaves are all clustered at the summit of the short, abrupt trunk which is tesselated all over with leaf-scars.

FIG. 693.   1. Branch of Thuja occidentals, with strobiles

FIG. 693. - 1. Branch of Thuja occidentals, with strobiles. 2. A magnified branchlet with a zone of staminate flowers. 8. A carpellary scale with the two winged seeds. 4. A vertical tranverse section of one of the seeds, showing the embryo, etc. 5. The immature, erect ovules. 0. One or the ovules enlarged, showing the micropyle at top. 7. Branch of Abies Americana. B. Scale, with the bract 9. Scale with immature ovules. 10. Scale with ripe seeds. 11. A pair of loaves of Pinus resinosa. 12. Anther of Pinus sylvestris. 13. Scale of the cone, with the ovules turned downward. 14. Staminate scale of Cupressus, with pollen. 15. Fertile scale, with many erect ovules.

Province, ENDOGENS,

Or Monocotyledons. Phaenogamous Plants having a stem without the distinction of bark, wood and pith, composed of thread-like bundles of trachenchyma imbedded irregularly. in the general cellular mass, the newest interior, not forming layers in growth. Leaves mostly parallel-veined. Flowers very generally 3-merous. Embryo with one cotyledon, rarely with 2 alternate and unequal.

Class III. PETALIFERae. Plants of the endogenous structure, the flowers normal and complete with a whorled perianth, or the perianth wanting - in either case destitute of glumes.

Cohort 5, SPADICIFLORae. Endogens with flowers having no perianth or a scaly one, and borne on a thickened rachis (spadix) which is usually enveloped in a spathe.