THE PALAEOTROPICS 



193 



the blue-flowered Exacum, Hedyotis, Strobilanthus and Ceropegia 



( Asclepiadaceae) . 



Orchids are quite common, a beautiful white epiphytic species 

 {Coelogyne odoratissimum) being especially abundant. Other 

 orchids noted were species of Dendrobium, Satyrium, Oberonia, 

 Listera. 



Ferns are well represented, especially in the moist shady forest, 

 but some species are characteristic of the open and drier plae. 3. 

 On rocky banks, Gleichenia dichotoma (linearis), a cosmopolitan 



Fig. 55. — Botanical Garden, Hakgala, Ceylon. 



species, forms thickets, and associated with it is an equally wide- 

 spread club-moss, Lycopodium cernuum. In the shady localitn ts 

 one may find some of the filmy ferns (Hymenophyllaceae), but 

 these are not particularly abundant. In sheltered gullies are fine 

 tree-ferns, the most abundant one being Alsophila crinita. In 

 the moist grassy meadows an adder-tongue fern, Ophioglossum 

 reticulatum is not uncommon, and occasionally a related fern, 

 Botrychium lanuginosum is met with. The boggy meadows also 

 harbor sundews (Drosera spp.), and bladder-weed (UUricularia 

 sp.), as well as several club-mosses, two of which, Lycopodium 

 clavatum and L. Carolinianum are characteristic boreal species. 



