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MORPHOLOGY 

 (7) GNETALES 



General character. This group comprises three very distinct genera: 

 Ephedra, with about fifty species distributed throughout the arid regions 

 of theMediterranean basin and adjacent Asia, and also in the arid regions 



516 



FIGS. 511-516. Ephedra: 511, branches bearing ovulate strobili; 512, branches 

 bearing staminace strobili; 513, staminate strobilus, showing starainate "flowers" in 

 axils of bracts; 514, ovulate strobilus; 515, an ovulate "flower"; 516, decussating 

 bracts of the ovulate strobilus. After WATSON. 



of western North America and South America; Tumboa (often called 

 Welwitschia), represented by a single species in the arid districts of 

 western South Africa ; and Gnetum. with about fifteen species distrib- 



