FLORA. OF ST. CROIX AND THE VIRGIN ISLANDS. 9 



a very dry structure, and a dense cover of scales for protection, whilst 

 others again, such as Anona squamosa, which are apparently without 

 any means to resist the effects of dry weather, have no other remedy left 

 than to shed their leaves during a part of the year, and thus preserve 

 their existence at the temporary sacrifice of their vegetative organs. 



All the forms mentioned above are of very slow growth, and, with the 

 excex)tion of a few that are used for burning charcoal, of scarcely any 

 importance either to man or animals, for which reason the districts oc- 

 cupied by them as a rule present a very desolate and uninviting appear- 

 ance. 



"Where the climate becomes sufficiently moist, and the soil in conse- 

 quence thereof more decomposed and fertile, the forest appears in place 

 of the Croton vegetation, on the uncultivated lands, especially in ravines 

 and on steep declivities, which do not allow of cultivation or grass- 

 farming. As nearly everywhere in the tropics, the forest here is com- 

 posed of many different species of trees mixed together, a gregarious 

 growth being very rare. From the forests of moister tropical countries, 

 however, the woods in these islands are distinguished by possessing a 

 quantity of forms with thin, herbaceous leaves, which for this reason 

 shed their foliage during a part of the year, thus combining the appear- 

 ance of the woods of colder climates with the dark evergreen forms of 

 the intertropical countries. Some of these species with deciduous 

 foliage have two periods for flowering: one precocious in the first 

 months of the year, when the small quantity of rain seems insufficient 

 to produce both leaves and flowers at a time, and another later in the 

 year, when both foliage and blossoms are vigorously developed by the 

 increased moisture of the summer. The evergreens for the same reason 

 have a less fixed and more unlimited time for flowering, and seem to 

 show their reproductive organs whenever the quantity of rain becomes 

 sufficient for producing them besides maintaining the already existing 

 foliage. Among the great variety of evergreen forms of trees and 

 shrubs, I shall here only mention as the most common several species 

 of Anona; of Guttiferae, such as Calopkyllum Calaba and Clusia rosea; 

 of Sapotaceae, such as Sideroxylon, Chrysophyllum, Lucuma, and Di- 

 pholis ; of Kutacese, as Zanthoxylum and Tobinia ; of Lauraceae, as oS.ec- 

 tandra and Oreodoxylon, as well as many others, for the details of which 

 I beg to refer to the systematical part of my treatise. Others are pos- 

 sessed of aerial roots by which to affix themselves to the stems of trees 

 and rocks, as several species of Ficus ; others again are vines, such as 

 Bignonia, Serjania, Gouania, and Cissus. 



