16 



CYCADALES 



[CH. 



to the upper sloping sides of the rachis which forms a prominent ridge between 

 the rows of leaflets, and characteristic oval scars are left on the fall of the 

 pinnae (fig. 387, D, G'). The lamina in most species contains several veins 

 more or less parallel to the margins and often much more prominent on the 

 lower than on the upper surface. 



FIG. 387. Cycadean fronds. A, Cycas circinalis; B, Macrozamia Fraseri; 

 C, Macrozamia Denisoni; D, Encephalartos caffer; E, F, Dioon edule from 

 below and above; G, Encephalartos Frederici-Guilielmi, G', side-view; 

 H, Ceratozamia mexicana; I, Cycas circinalis, lower part of young frond. 



Zamia. In Zamia angustifolia (fig. 385, C) and Z. linifolia the pinnae 

 are long and very narrow: the other extreme is represented by Z. Wallisii 1 

 (fig. 388) with broad ovate segments reaching a length of nearly -5 metre 

 and attached to the rachis by a short stalk; the veins are prominent 

 and dichotomously branched. Other forms of pinnae are represented by 

 Z. integrifolia, Z. floridana, and Z. Loddigesii (figs. 389, 390, 395). The 

 1 Braun, A. (75 2 ) p. 376. 



