94 



shortly stalked. There are six genera in the West Indies, distin- 

 guished by the character of the indusium, habit and cutting of 

 the leaves. 



Cyathea arborca is the oldest and best known of the West In- 

 dian tree ferns, and the only one common to most of the islands, 

 many of the species being found only on the islands on which 

 they were originall)' described. It occurs at an elevation of 

 I, GOO to 2,000 feet and forms a handsome tree with a spread of 

 14 to 18 feet. Above this it is replaced by a similar but larger 

 species of Alsophila. Cyathea arborca and C. clcgaus are notice- 

 ably distinguishable by the caudex, that of the former being 

 smooth while that of the latter is very rough and shaggy. C. 

 jiigrcsccns is common to Jamaica and Cuba. C. iusignis is a 

 handsome plant, but as only two were seen, and these repre- 

 sented, perhaps, 200 years growth, thc}^ were not taken for 

 specimens, but notes were made on the trunk characters. A 

 fine specimen, brought by Professor Earle, is in culti\'ation at 

 the conservatory of the Botanical Garden. Of the 16 species 

 of Cyathea, which are not doubtful, 13 are endemic in Jamaica; 

 three are known only from type specimens. The sharp prickles 

 of these and other species secrete a poison, and wounds from 

 them are very painful, so tiiat collecting on the steep hillsides is 

 likely to be attended with considerable discomfort. The genus 

 Alsophila has three species which are well known. A. aniiata, 

 occurring at 4,000 to 5,000 feet elevation, has a usual height of 

 40 to 45 feet and is the most graceful plant of the island. It is 

 armed only with weak bristles. Alsopliila aspcra, which is a lower 

 tree, has smooth leaves but prickly petioles. It occurs at about 

 1,500 feet elevation. Two of the species are endemic. Hemi- 

 tclia has one species described early in the last century, which is 

 probably extinct and two others very little known. 



A species of Lophosoria has a dense bloom on the under side 

 of the leaves and is somewhat xcrophytic in habit. It has 

 merely a woody base. 



Cncmidaria is distinguished by its habit and the cutting of 

 its leaves. It has veins uniting near the midrib to form 

 me.shes. 



