The paper deals with a detailed account of the vegetation of the Parambikulam and Aliyar Submergible areas in Kerala and Madras States. Intensive botanical exploration was carried out in different seasons of the year during 1962-63.
The Parambikulam submergible area is situated in Trichur District, Kerala State at an altitude of ±610 m. It covers 20.8 sq. km of virgin forests and is formed by the construction of the dam across the Parambikulam river. The forest presents different layers of vegetation which is a continuation of that of Malabar Province and the Deccan Province as described by Sir J. D. Hooker. The luxuriant and thick vegetation comprises 159 species of Angiosperms belonging to 63 families. The families Papilionaceae and Euphorbiaceae are dominant. This vegetation includes several economically important timber yielding trees and medicinal plants.
The Aliyar submergible area is situated in the Coimbatore District, Madras State and it is formed by the dam constructed across the Aliyar river. It covers an area of 6.5 sq km. The vegetation is mostly the scrub jungle type with the combination of dry deciduous type. It constitutes 292 species of Angiosperms belonging to 71 families. The families like Papilionaceae, Euphorbiaceae, Gramineae, Cyperaceae, Acanthaceae, Malvaceae and Labiatae are largely represented.