238 



The Plant Worux 



BOOKS AND CURRENT LITERATURE. 



Flora of the Islands of Margarita and Coche, Venezuela, by 

 John Robert Johnston, stands as Contribution No. XXXVII 

 from the Gray Herbarium of Harvard University, bearing date 

 of June, 1909. Some of the more important data and conclu- 

 sions, for the most part in the words of the author, are as follows : 



The island of Margarita is the largest of the Venezuelan 

 islands that extend along the coast from Curacoa to Trinidad, 

 being 67 kilometers long and 32 wide. The mountains of the 

 eastern end rise to an altitude of 795 meters and the peak at the 

 western end a little higher. As a whole it is a very dry island, 

 having, as compared with other tropical districts, almost no rain- 

 fall. None the less, there are dense woods covering the moun- 

 tains above 400 meters that collect and retain the moisture of 

 the clouds which envelop them, thus furnishing a source for 

 small streams below. 



The flora of Margarita, as thus far collected, consists of 644 

 species, of which 40 are cultivated and 66 are cosmopolitan 

 There are 419 common to tropical America. »Of these 37 are 

 limited to the West Indies and 82 to South America. Thus it 

 is evident that the flora is of a general character in that the ma- 

 jority of the species are common with the West Indies and to 

 South America. Members of the Leguminorsae are the most 

 common plants, while the Compositae are represented chiefly 

 by inconspicuous weeds, and there is, as would be expected, 

 a marked lack of grasses and sedges. The Cactaceal, which cover 

 the plains for miles, include 12 species. The Bromeliaceae are 

 characteristic and conspicuous. Among other groups character- 

 istic of tropical regions occurring on this island, are Melastom- 

 aceae, Aroideae, Piperaceae, Loranthaceae, and various Filices 

 such as Trichomanes, Hymenophyllum, and Cyathea. 



In considering the local distribution of the plants of the 

 island the author first discusses their occurrence in regions of 

 different vegetative conditions. The lagoons are bordered by 

 mangroves — Rhizophora Mangle, Laguncularia racemosa, and 

 Avicennia nitida — and on the sandy stretches adjacent are such 

 low succulents as Batis, Salicornia, and Trianthema. On the 

 plains stretching inland are great numbers of the melon cactus, 



