243 



Tribe II. GYMNOSPERM^. 



Synobhizs 



, Rich. Anal. du. Fr. Eng. ed. 81. (1819).— Phanerogames Gvmnospebmes, Ad. 

 Brongniart Vegct. Foss. 88. (1828.) 



These have nearly an equal relation to flowering and flowerless plants. 

 With the former they agree in habit, in the presence of stamens and pistils, and 

 in their vascular tissue being complete ; with Ferns and Lycopodiums, among 

 the latter, they also accord in habit, in the peculiar gyrate vernation of the 

 leaves of Cycadeaj, in their spiral vessels being imperfectly formed, and in the 

 reproductive organs being less complete than in other flowering plants ; the 

 pistils wanting a pericarpial covering, and receiving impregnation directly 

 through the foramen of the ovulum, without the intervention of style or stigma, 

 and the stamens consisting of leaves imperfectly contracted into an anther bear- 

 ing a number of pollen-cases upon their surface. So great is the resemblance 

 between Lycopodiums and certain Coniferae, that I know of no external charac- 

 ter, except size, by which they can be distinguished ; and it is, at least, as pro- 

 bable that some of those vegetables found in the ancient Flora of the world, 

 which have been considered gigantic Lycopodiums, are Coniferae, as that they 

 are flowerless plants. Gymnospermse are known from all other Vasculares by 

 the vessels of their wood having large apparent perforations, to which nothing 

 similar has yet been seen elsewhere. It is not, however, on this account to be 

 understood that these differ in growth from other Exogenous plants ; on the 

 contrary, they are essentially the same, deviating in no respect from the plan 

 upon which Exogenous plants increase, but having a kind of tissue peculiar to 

 themselves. 



LIST OF THE ORDERS. 

 227. Cycadere. | 228. Coniferse. 



CCXXVII. CYCADEiE. 



Cycadeb, Rich, in Pers. Synops. 2. 630. (1807) ; Brown Prodr. 346. (1810) ; Kunth in Humb. 

 et Bonpl. Nov. Gen. et Sp. 2. 1. (1817); Synops. 1. 349. (1822); R. Brown in King's Voy- 

 age, (1825) ; Rich. Memoire, 195. (1826 ; Ad. Brogniart in Ann. des be. lb. 589. (1829.) 



Diagnosis. Naked-seeded mucilaginous dicotyledons, with a round or 

 cylindrical undivided trunk, and pinnated leaves having a gyrate vernation and 

 parallel veins. 



Anomalies. 



Essential Character.— Flowers dioecious, terminal. Staminiferous monandrous, naked, 

 collected in cones ; each floret consisting of a single scale (or anther) bearing the pollen on its 

 under surface in 2-valved cases which adhere in clusters of 2, 3, or 4. Pvstilhferous either 



