﻿EXISTING AND FOSSIL CYCADS COMPARED. 



I 9 I 



/units Saporta is from the Miocene of Koumi, in Euboa, and the genus Cycas is very 

 ancient, being represented by a number of undoubted species, based on both leaves 

 and fruits from the Mesozoic. Cycas Steenstrupi Heer, from the Upper Cretaceous 

 of Atane, in Greenland, is of especial interest and beauty, the type consisting in a 

 fine frond nearly two feet in length and a carpellary leaf with seeds attached, both 

 leaf and fruit being closely placed imprints on the same slab, and unquestionably 

 representing a rather dwarfish, extinct species of Cycas. Furthermore, it is very 

 suggestive that a Cycas-like carpellary leaf, accompanied by Zamites-like fronds, 

 occurs in the lower Keuper (31), while characteristic leaves, with copious pinnation 

 and linear-pointed pinnse with one nerve, are found as far back as the Carbonif- 

 erous limestone. 



Though of great interest in the present connection, neither space nor time will 

 permit a general survey of the generic and specific distribution of the existing 

 cycads, considered especially 

 with reference to appearance 

 and habits of growth. In 

 lieu of such extendedjtreat- 

 ment it may, however, suffice 

 to include here a series of 

 habitus illustrations from the 

 several genera, together with 

 brief notes on Za»u'a, the 

 most widely distributed and 

 otherwise interesting of occi- 

 dental forms. 



Fig. 104. — Zamia Roezli. X / ; . A low-growing branched form recalling quite 

 exactly some of the branching Cycadeoideas from the Black Hills. These 

 trunks exhibit rapid excision of the armor, and the branch to the left bears 

 three staminate cones. The fronds (fully 1.5 meters high) are relatively 

 very large and the petioles are thickly beset with heavy, rather blunt-ended 

 thoms or prickles. 



ZAMIA. 



The genus Zamia is 

 typically American. It com- 

 prises about thirty species, 

 or rather more than are 

 included in any two of the 

 other cycad genera. It is well 

 represented throughout the West Indies and the Central American and Mexican 

 mainland, which, together with Florida and the Bahamas and the northern 

 portions of South America, constitute the limits of its habitat. 



The Zamia trunks are mostly low-growing and freely-branching forms. Two, 

 Z. pseudoparasitica Yates and Z. Poppigiaua, are Peruvian and Panama epiphytes 

 (on tree trunks). Z. pygmaea Sims, of the Antilles, is the smallest of living cycads, 

 its fronds being only 10 or 12 cm. long; and most species of the genus are low- 

 growing, though some have large fronds. Various species, as Z. jloridana, in/egri- 

 folia, pumila, etc., are distinctly subterranean in trunk habit. The pinnules of the 

 Zamias present many gradations, from linear forms quite as narrow and long as 

 pine needles to elliptical or somewhat spatidate, thick, and fleshy forms like those 

 of Z. fiirfuracca, which strongly recall the blades of certain species of Cordaitese. 



