^^^^ Yaf?;( BOTANIC 

 ISSUED ^''"^^y^-LBHlTW 



No. 7.— CONTRIBUTIONS FROM THE GRAY HERBARIUM 



OF HARVARD UNIVERSITY. NEW SERIES.— NO. 



XXXVII. FLORA OF THE ISLANDS OF 



MARGARITA AND COCHE, 



VENEZUELA. 



BY JOHN ROBERT JOHNSTON, M. S. 



Contents. 



Page. 

 General considerations on the flora of Venezuela — Variety of vege- 

 tative conditions — Desirability of further collecting — Explo- 

 ration and botanical work ....... 163 



Flora of the Island of Margarita 167 



Introduction .......... 167 



Physical features — Topography — Rainfall and clouds — 



Temperature 168 



Catalogue of plants ........ 175 



The economic plants of Margarita ...... 270 



Distribution of the plants — Regional distribution — Group- 

 ing — Paucity of specimens — Adaptation and barriers to 

 dispersal — Seasonal distribution ..... 278 



Composition of the flora — The cultivated, the cosmopolitan, 

 and the plants of restricted distribution — The variety of 

 plants and the groups most largely represented . . . 283 



The flora of the Island of Coche 288 



Description of the vegetative conditions ..... 288 



Catalogue of plants 291 



Comparison of the flora of Margarita and Coche with that of other 

 regions — Methods of comparison — Other Venezuelan 

 islands — The mainland — The West Indies — Southern 



United States 293 



Conclusion 301 



Literature of geographical and botanical publications . . . 304 



General Considerations on the Flora of Venezuela. 



Cr. Professor Goebel's ('91) most interesting account of the vegeta- 



cr tive conditions to be found on the Cordilleras of Merida in Venezuela 



oc is descriptive of an excellent field for botanical research. Within 



150 kilometers (93 miles) of the shores of Lake Maracaibo the moun- 



163 



