igo 



MORPHOLOGY 



Conclusions. — The characters presented by this group are a com- 

 bination of the characters of ( jcadofilicafes, of Cycadales, and of char- 

 acters peculiar to itself. In lateral branches, ramentum, direct leaf 

 traces, and synangia, it resembles Cycadolilicales and Filicales. In 



general habit and 

 anatomy it re- 

 sembles Cycadales. 

 In its bisporangiate 

 strobilus, its united 

 and pinnate and 

 synangium-bearing 

 stamens, its mix- 

 ture of sterile and 

 fertile megaspo- 

 rophylls bearing 

 terminal ovules, 

 and its peculiar 

 embryo, it is unlike 

 any other gymno- 

 sperm group. 



(3) Cycadales 



General character. 

 — The cycads are 

 tropical plants, in- 

 cluding almost one 

 hundred species, 

 constituting nine 

 genera. They are 

 distributed almost 

 equally between the 

 oriental and oc- 

 cidental tropics, 

 Cycas being the 

 conspicuous orien- 

 tal genus, and Zamia the conspicuous occidental one. The cycads are 

 the modern living representatives of the line that began with the 

 Cycadofilicales of the Paleozoic, and was continued by the Bennet- 

 titales of the Mesozoic. 



Fig. 433. — Cycas media (middle and right) and C. Norma n- 

 byana (left), from oriental tropics. — After F. von Muixer. 



