Vol.7 



No. 3 



TORREYA 



March, 1907 



ON SOME DISTRIBUTION FACTORS IN THE SIERRA 

 MAESTRA, CUBA 



By Norman Taylor 



Botanical collecting in the tropics constantly reminds one of 

 the difficulty of forming any real idea of the factors that govern 

 the distribution of plants. 



In a survey of the mountains west of Santiago, Cuba, many 

 plants of very curious distribution were met with. To travel for 

 four weeks over a somewhat restricted but heterogeneous country 

 and find only a single individual oi Ainyris clendfcra, and also single 

 specimens of CalopJiyllnm Calaha, of a certain Oncidhnn, and of an 

 unnamed Euphorbia, makes one wonder what are the factors that 

 govern such sporadic occurrences. And these are not the only 

 species that have apparently only individual representation, for 

 here and there throughout the various habitats visited we came 

 across trees, shrubs and even some herbaceous plants that were 

 never seen again. This remarkable feature of tropical forests has 

 often been noted before,* but no reasonable explanation is 

 forthcoming. 



Besides this occurrence of lone individuals, we find also what 

 might be called "species centers."! That is, some species 

 would be found in a very restricted area, and then either not be 

 seen again, or else found in some distant but ecologically 

 related habitat. Only a very few plants were observed in this 

 state, which after all may be more a matter of coincidence or 

 accidental dispersion than any well-defined system of distribution. 

 The most noticeable of the species having these apparent distri- 



* Warming, E. On the Vegetation of Tropical America. Bot. Gaz. 27 : 2. 

 1899. 



t Kurz, S. Report on the Vegetation of the Andaman Islands, 16. 1870. 

 DC 

 <i; [No. 2, Vol. 7, of ToRREYA, comprising pages 21-48, was issued February 28, 1907.] 



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