130 THE TLANT WOKLU. 



the more conspicuous. The most important and best known o' 

 these fortifications are Morro Castle anrl Cabanas. Built as a 

 defence against the " flesh and the devil," Morro only has expe- 

 rienced one siege, and yet both are being rapidly disintegrated 

 through the agencies of nature. Morro is much the older, hav- 

 ing been completed in 1597, while Cabanas was begun in 1763 

 and completed in 1774. And yet Cabanas looks as old or older 

 than Morro. For generations these immense piles of masonry 

 have stood as military scarecrows to all the rest of the civilized 

 world, only to be destroyed by the slow but ever working forces 

 of nature. 



Crossing the harbor from Havana, the visitor lands at the foot 

 of a covered road which leads up to the south entrance of 

 Cabanas and into " Los Fosos de los Laureles " (the laurel ditch) 

 with its thick walls of masonry forty feet in height. \\'ithin this 

 moat are a number of very large laurel trees (Ficiis iiitida) and 

 at various places through this and other moats are numerous 

 plants of many species. Of the trees, the most common are the 

 Delonix rcgia (royal poincianas), Ficiis iiitida (laurel) and occa- 

 sionally some others. Among the smaller plants the following 

 species are very abundant: Riciiuis sp., Solauuiii vcrbasifoUnm 

 and other solanaceous plants, Ipoiiia:a doiiiciii^iiiciisis. Hauielia 

 patens, Moiiiordica charantia, Cordia sp., Tribiihis cistoides, 

 Iresinc paiiiciilata. Bidriis hicaiifha, J'aclwlla fanicslaiia, Stachy- 

 tarpheta jainaicciisis. Tunicra uluufolia, Porfiilaca sp., Stcno- 

 lohinni staiis and a number of Compositge and Gramine?e. 



Many of the above mentioned plants grow in holes and crev- 

 ices of the walls, but by far the most conspicuous of these wall 

 plants is Rhytidophy/hiin crcmilatuni (see Fig. 19) which grows 

 everywhere over the surface of the walls. The plant belongs to 

 the family Gesneracese, and the genus is restricted to the Greater 

 Antilles. This species, though comparatively rare, grows upon 

 the rocks along the coast. The wonder is how this vigorous 

 plant can secure a foothold and nourishment in these walls, and 

 yet it seems to take advantage of every opening, however small, 

 and grows in luxuriant abundance. Its work as a disintegrating 

 factor is undoubtedly very important. 



