Gymnogens.] 



CYCADEACE^. 



>23 



Order LXXIII. CYCADEACEiE.— Cycads. 



Cvcadeje, Rich, in Pers. Si/nops. 2. 630. (1807) ; Broim Prodr. 346. (1810) ; Kunth in Humb. et Bonpl. 

 Nov. Gen. et Sp. 2. 1. (1817) ; R. Brown in King's Voyage, (1825); Rich Mhnoire, 195. (1826) ; 

 Ad. Brongniart in Ann. des Sc. 16. 589. (1829) ; Meisner, Gen. p. 353 ; Miguel in Linncea, 17. 675. 

 — Cycadeaceae, Ed. prior, (1836) ; Endl. Gen. xxxviii. 



Diagnosis. — Gymnogens with a simple continuous stem , parallel-veined pinnate leaves, and 

 antheriferous cone-scales. 



Small ti'ees or shinabs, sometimes resembling Palm trees in their aspect. The stems 

 are either simple and cyUndrical, or spheroidal, or diehotomously branched, and in all 

 cases strongly marked with 

 the lozenge-shaped scars of 

 broad woody leaf-stalks. 

 Internally the stem consists 

 .N^>x of a mass of pith, traversed 



by woody bmidles, and rings 

 of woody matter, sometimes 

 UTegularly disposed, some- 

 times collected into regular 



Fig. CLI. 



and numerous concentrieal 



circles, always pierced by 



medullary plates. The wood 



consists of glandular woody 



tissue and spiral vessels. 



The leaves are pinnated, 



hard and woody, perennial, 



generally circinatc when 



young, but in some instances 



Fig.CLII. ^^^ . ^j^g leaflets have fine 



simple veins, and are placed somewhat obliquely on their petiole, from which they finally 



disarticulate. (Miquel regards these leaves as a sort of branch, "rami sc'issi."— Linncea, 



I.e.) Flowers ^ ? , perfectly destitute of all trace of calyx and corolla. ^ collected in 



terminal cones, consisting of scales covered over their lower side with anthers which are 



one-celled, often collected in twos and threes, and split longitudinally. 



Pollen hyaline, 



Fig. CLI.— Cycas circinalis ; 1. a portion of a female frond ; 2. section of the naked ovule ; ^. ripe 

 fruit; 4. embrj'o. 

 Fig. CLII. — Leaves of Zamias. 



