EXOGENOUS OB DICOTYLKDONOUS PLANTS. 



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927. Ord. CycadaceiE {Oycas Family). Tropical plants, with an 

 unbranclied cylindrical trunk, increasing, like Palms, by a single 

 terminal bud ; the leaves pinnate and their segments more or less 

 rolled up from the apex (circinate) in vernation, in the manner of 

 Ferns. Flowers dioscious ; the staminate in a strobile or cone ; the 

 pistillate also in strobiles, or else (in Cycas) occupying contracted 



and partly metamorphosed leaves ; the naked ovules borne on its 

 margins. — Ex. Cycas, Zamia. — A kind of Arrowroot is obtained 

 from these thickened stems, or caudexes, as from our dwarf Florida 

 species (tlie Coontie of the aborigines) ; and a coarse Sago from 

 the trunk of Cycas. 



FIG. 1189. Zamia iategrlfolia (the Coontie of Florida). 1190. Section of the sterile ament. 

 1191. One of its scales detached, bearing scattered anthers. 1192. Fertile ament, from which 

 a quarter-section is removed. 1193. A pistillate flower, consisting of two ovules pendent from 

 the thickened summit of the carpellary scale. 1194. A drupaceous seed, from which a part of 

 the pulpy outer portion, at the apex, is removed. 1195. Vertical section through the seed (of 

 the natural size], showing the pulpy outer coat, the hard inner integument, the albumen, and 

 the embryo. 



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