INTRODUCTORY CHAPTER. XXXV 



more vigorous, but in no place sufficiently so to call for the designation of forest, 

 nor is there anything in the way of fine timber. But in the valleys, wherever 

 there is any degree of moisture, small trees of some 20 to 25 feet, with smaller 

 shrubs packed so densely as to exclude the light from above, linked together by 

 far-reaching lianes, and underlain by a thick under-scrub of fern and herb, 

 make an almost impenetrable thicket, and produce a verdure quite tropical in 

 its luxuriance. In this district the flora is of a tropical old-world type, having 

 representatives of such genera as Elceocarpus, Grewia, Boswellia, Ormocarpum, 

 Dirichletia, Musscenda, Sideroxylon, Euclea, Jasminum, Secamone, Porana, 

 Orthosiphon, Clerodendron, Lasiosiphon, and various genera of Acanthacege. 



Once out of the valleys and upon the plateaux the scene is essentially 

 different. Wide barren stretches of grey limestone, or undulating prairie-like 

 downs, extend on every side unrelieved, save by an isolated Dracaena, or tree- 

 euphorbia of stiff erect habit, looking like the remnant of the vegetation of 

 of some old geological epoch, or where a lake-like depression, with its brown 

 earth sparingly coated with green herbage, often of rank luxuriance, intervenes. 

 And when we reach the higher altitudes on the granitic range, the vege- 

 tation impresses one at once with its sub-temperate character. The arborescent 

 type has almost entirely disappeared. Shrubby composites, such as species of 

 Psiadia, Pluchea, and Euryops, and succulent forms of Senecio are found, also 

 crowds of Helichrysum many of them strongly aromatic, and scenting the air 

 under the stimulating sun-rays ; and quaint types, such as those of Thamnosma, 

 Nirarathamnos, Graderia, Cephalocroton, Cocculus Balfourii, and others, are 

 frequent ; twiggy narrow-leaved herbs form a dense deep carpet on the soil, 

 interrupted here and there by a protruding lichen-covered boulder, and for all 

 the world like the covering of heather on a northern moor ; whilst within the 

 shade of the boulders, or in the moisture of the overhanging cliffs in the 

 ravines, bright green herbs, such as species of Galium and Gypsophila, nestle 

 in beds of liverwort and moss. 



The flora, as we know it, is a pretty extensive one, much more so than was 

 anticipated. It comprises 828 species, and of these 575 are Phanerogams and 

 253 are Cryptogams. 



Of the 575 Phanerogams, the ten following plants, which had been evidently 

 planted where they were found or were only recent escapes from cultivation 

 in the vicinity of habitations, may be deducted from the total before making 

 a further analysis, viz., Gossypium barbadense, Ruta graveolens, Citrus Auran- 

 tium, Indigo/era tinctoria, Tamarindus indica, Fceniculum vulgare, Ocimum 

 canum, Ricinus communis, Phoenix dactylifera, Borassus Jlabelliformis. Amongst 

 the remaining 565 species of Phanerogams are many which are undoubted 

 introductions and weeds of cultivation ; but as they are to a greater or less 

 degree established on the island, and may in time form important constituents 



