245 



TiuBE II. GYMNOSPERM^. 



SvNORHiz^'E, Rich. Anal, du Fr. Eng. ed. 81. (1819). — Phanerogames Gysino- 

 SPERMES, Ad. Brongniart Veget. 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 sexes, 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 Cycadete, in their spiral vessels being imperfectly formed, and in 

 the sexes being less complete than in other flowering plants; the females 

 ■wanting a pericarpial covering, and receiving impregnation directly through 

 the foramen of the ovulum, v/ithout the intervention of style or stigma, and 

 the males consisting of leaves imperfectly contracted into an anther bearing 

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

 between Lycopodiums and certain Coniferse, that I know of no external 

 character, except size, by which they can be distinguished ; and it is, at least, 

 as probable that some of those vegetables found in the ancient Flora of the 

 world, which have been considered gigantic Lycopodiums, are Coniferss, as 

 that they are flowerless plants. Gymnospermae 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. Cycadese. j 228. Conifers. 



CCXXVII. CYCADE^. 



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

 Humh. el Bonpl. Nov. Gen. et Sp. 2. 1. (1817); Synops. 1. 34!>. (1822); R. 

 Brown in Kinq^s Voyage, (1825); Rich. Memoire, 195. (1826) ; Ad. Brongniart iti 

 Ann. des Sc 16.58.9. (1829.) 



Diagnosis. Naked-seeded mucilaginous dicotyledons, with a round 

 or cylindrical undivided trunk, and pinnated leaves having a gyrate verna- 

 tion and parallel veins. 



Anomalies. 



Essential Character — F/otoers dioecious, terminal. Males 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. Females either 

 collected in cones, or surrounding the central bud in the form of contracted leaves without 

 pinna>, bearing the ovula on their margins. Ovula solitary, naked, with no other pericar- 

 pium than the scale or contracted leaf upon which they are seated. Embryo in the midst 



