The west coast evergreen forests are characterized by the bewildering multiplicity of life forms and overpowering preponderance of greenness.  The forest is lofty, dense and  characterized by heavy species density. The top canopy is almost unbroken comprised   of   tall trees, 45m   or   even   more   in height with a luxuriant growth of evergreen trees of different sizes and shapes arranged in serial tiers. Above the ground layer of herbs and shrubs, the crown of the trees form three or more super imposed stories, but strata of trees are sometimes never clearly defined as they are continuously growing. The crown of trees in each storey has a distinguished shape. In the top storey the trees are usually umbrella-shaped, in the middle they are more or less candle flame-shaped and are markedly conical at the bottom.   Buttressed roots are characteristic in this type.  The following species  exhibit buttress formation,  e.g.  Elaeocarpus tuberculata,    Cullenia   exarillata,   Palaquium    ellipticum, Poeciloneuron  indicum. The boles are long, cylindrical, with thin, smooth barks.  The leaves are thick and glossy, rarely finely  pinnate or hairy and are very often white or  pink  when young. Another feature of this type of forest is the phenomena of cauliflory.  The presence of Cullenia  exarillata,  Poeciloneuron indicum  and  the  high proportion  of  Mesua,  Calophyllum,  etc. indicate  that  west  coast  tropical  evergreen  forest  of  this sanctuary   belongs   to   high   level   evergreen   forest   of  Chandrasekharan    (1962   a,b&c).   Cullenia    exarillata and Poeciloneuron  indicum are exclusively limited to this type.  The most noticeable difference from the low evergreen forest is the high percentage of occurrence of above species when the precipitation is particularly heavy or the soil moisture particularly favourable.

This forest type is the major vegetation in the sanctuary and it is found at Rosemala, Kallar-Pandimotta, along the banks of Umayar and Uruliyar.

Trees in the upper storey are Dipterocarpus indicus, Calophyllum polyanthum, Mesua ferrea, Poeciloneuron indicum, Mangifera indica, Cullenia exarillata, Vateria indica, Artocarpus heterophyllus, Gluta travancorica, Hopea parviflora, Hopea racophloea, Lophopetalum wightianum, Kingiodendron pinnatum, Dysoxylum malabaricum, Diospyros ghatensis, Palaquium ellipticum, etc.

The trees of middle storey are Garcinia spicata, Polyalthia coffeoides, Elaeocarpus serratum, Fahrenheitia ceylanica, Aglaia lawii, Drypetes elata, Garcinia gummi-gutta, Buchanania lanceolata, Syzygium gardneri, Gordonia obtuse, Aglaia barberi, A. perviridis, Xylopia parvifolia, Aphanamixis polystachya, Humboldtia decurrens, Hydnocarpus alpinia, etc.

The lower storey comprises of Goniothalamus rhynchantherus, Miliusa wightiana, Meiogyne ramarowii, Orophea uniflora, Erythroxylum lanceolatum, Acronychia pedunculata, Aglaia simplicifolia, etc.
The shrubby plants are mostly Dichapetalum gelonioides, Strobilanthus ssp., Lasianthus ssp., Glycosmis macrocarpa, Alpinia malaccensis, Leptonychia caudate, Clausena austroindica, Phaeanthus malabarica, Popowia beddomea, Tabernaemontana gamblei, etc.