s?EKMAToriivri:s 



22f) 



uted throughout the tropics of both hemisphtres. Gnctales have always 

 attracted attention from the fact that in certain characters they resemljle 

 angiosperms more nearly than do the other gvmnospcrms. 



I-H;. 5x7. — Tunil'i'u, showing thr lica\y conical itody and the two-loliciJ cruwn 

 ing two broad paralicl-veined leaves (iti the photograjjh spHt into shreds) and strohilus- 

 bearing branches. 



Sporophyte. — The species of Ephedra are straggling shrulss, with 

 long-jointed and fluted green stems, and scalelike o[)posite leaves f(jrm- 

 ing 'at each joint a two-toothed sheath 

 (tigs. 511, 512, 975). Tiimhoa has a 

 huge, woody, turnip-shaped Ijody, 

 whose crown hears a single pair of 

 elongated, strap-shaped, parallel-\-eined, 

 and persistent leaves (fig. 517). The 

 species of Giictii))i are small trees or 

 woody twiners with leathery, net- 

 veined, opposite leaves, resembling 

 those of dicotylediins (fig. 522). It 

 will be observed that a constant char- 

 acter of the group is the cyclic (op- 

 posite) leaves, a feature fouiid among 

 Coniferales onl\' in the Cupressineae. 



\'asnilay amiloiiiy. — It is in their 

 vascular anatomy that the Gnetales 



show a striking angiosperm chtiracter. 'J'he secondary wood does not 

 consist e-\clusi\'cly of Iracheids with bordered pits, as in the other gym- 



FlGS. 51S, 51U. —Ovulate (5 iS) and 

 slaniinatc (511J) strobili of Tiiilllma. 

 — S''"^, after \a-. .M.xiout and De- 

 < AiSNK; 5ig, after Hooker. 



