364 



MORPHOLOGY OF GYMNOSPERMS 



Beccari (4). Since that time there has been some fruitful investi- 

 gation, but the comparative inaccessibility of the material has made 

 the investigations less numerous and complete than the importance of 

 the group would justify. 



I. The vegetative organs 



The species of Ephedra are low straggling shrubs, with long- 

 jointed and fluted green stems, and opposite scalelike leaves connate 

 in a two-toothed sheath. True fohage leaves are generally lacking, 

 and the whole habit is suggestive of a shrubby Equisetum (fig. 404). 



Fig. 404. — Ephedra sp., growing near Tucson, Arizona. — From photograph by 

 D. T. MacDougal. 



Welwitschia is a plant of remarkable habit (figs. 405-407). The 

 very tough body has the shape of a gigantic radish, which rises little 

 above the surface of the ground, and whose crown is sometimes 3 . 5 

 to 4 . 5 meters in circiunf erence. The broad top is more or less con- 

 cave and somewhat two-lobed, and from the deep horizontal groove 



