CYCADALES 



91 



Leaflets vary greatly in size. In Ceratozamia longifolia they reach 

 40 cm. in length and 2.5 cm. in width; in Dioon spinulosum, 8.5-20 

 cm. in length and 10-17 mm. in width; in Dioon edule, 11-15 cm. in 



Fig. 83. — Dioon spinulosum: photograph of a surface view of the top of a large plant 

 cut longitudinally through the middle. The second cone dome from the top shows the 

 peduncle of the cone, and part of the peduncle can be seen in the cone dome just below 

 it, and in the lowest cone dome; one-half natural size. — After Chamberlain."' 



length and 4-8.5 mm. in width. The widest leaflets are those of 

 Zamia skinneri, 19-29 cm. long and 3-10 cm. wide. The narrowest 

 is in the Cuban Zamia angustissima, with leaflets about 7 cm. long 

 and I mm. wide. 



