It is climax vegetation of the area and is characterised by the luxuriance of its vegetation which consists of at least three tiers, the highest often attaining a height of 40 to 45 m.
Very often the trees are buttressed at base and the boles are clean, cylindrical, un-branched atleast up to two-thirds of their height and generally with a spreading or umbrella shaped crown at the top. The middle stratum is more or less candle shaped and the lower characteristically conical.
Heavy infestation of trees with orchids, aroids, mosses, ferns and lichens are common. Species with cauliflory are not rare. Trees with barks showing various features like smooth, flaky, fissured etc. are not uncommon. The multiplicity of species co-existing in complex biological equilibrium gives this type of forest the highest status viz. ‘climatic climax’.
Physiognomically three storeys can be recognised in this type of forests.
The dominant upper storey, which is usually of about 40-45 m in height, consists chiefly of Artocarpus heterophyllus, Bischofia javanica, Calophyllum elatum, Canarium strictum, Cullenia exarillata, Dipterocarpus sp, Drypetes elata, Dysoxylum malabaricum, Elaeocarpus tuberculatus, Holigarna arnottiana, Mesua ferrea, Palaquim ellipticum, Persea macrantha, Polyalthia coffeoides, and Vateria indica.
The second storey, which is about 15-30 m high, is comprised of Aglaia eleagnoidea, Actinoidaphne hookeri, Baccaurea courtallensis, Cinnamom malabathrum, Democarpus longan, Elaeocarpus serratus, Garcinia morella, Litsea wightiana, Myristica dactyloides and others.
The third storey which is of less than 15 m in height consists of small trees like Euonymus angulatus, Jambosa munroi, Memecylon sp., Xanthophyllum flavescens and also profuse shrubs like Lasianthus sp., psychotria sp., Solanum sp., Strobilanthus sp., Thottia siliquosa etc.
Monocots are few and their presence is localised. Important among them are Aranga wightii, Calamus sp., Pinanga dicksonii, Ochlandra sp., Oxytenenthera sp. and so on.
The ground flora is sparse and represented by species like Amomum sp., Arisaema leschenaultii, centlla asiatica, Elettaria cardamomum, Ophiorrhiza brunonis, Sarcandra sp and various species of Begonia and Elatostemma.
Woody lianas are represented by Caesalpinia bonduc, Entada pursetha etc while straggling ones with or without thorns are represented by Derris sp, Dioscorea sp, Smilax zeylanica, Thunbergia sp, Tragea involucrate and so on.
Epiphytes are represented by Fagraea zeylanica, various species of orchids, aroids and pteridophytes. Common parasites are Elytranthe sp, Loranthus sp, Viscum sp, etc.