PhD

Investigations on 'Habit and habitat analysis of select medicinal plants in
native and domestic environments' was undertaken at the Department of Plantation
Crops and Spices, College of Horticulture, Vellanikkara 680 654, Kerala, during the
period 1994-97. The first two experiments viz., survey and natural habitat analysis
were carried out in the Peechi forests and the last two viz., domestic environment
analysis and biochemical analysis in the College of Horticulture.
Ethno-medicines practiced by the 'Malayans' of the Peechi forests were
documented. The floristic survey identified 226 medicinal plants distributed over
several habits, habitats, plant families etc. There were 22 endemic, ten endangered,
six rare and nine threatened species. Extraction procedures of the drugs were
documented which varied with the plant and the part used. Practice of
substitution/adulteration was noticed in a few drugs.
Based on the survey, six species were chosen for detailed habitat analy-
sis. They were Piper longum, Naravelia zeylanica, Sida rhombifolia ssp. retusa,
Desmodium velutinum, Baliospermum solanifolium and Barleria prattensis.
Ten different habitats were selected in the MDF and they were
characterised by physiographic, climatic, edaphic and biotic variables. Habitats were
also grouped by cluster analysis.
The growth pattern of the select species in the forest showed that it was
almost linear upto November in all the habitats. Among the ten habitats, KC-I
appeared to be congenial for the natural growth and productivity of Piper.

Naravelia, Desmodium and Barleria. The habitat, KP-I appeared to support
maximum growth of Baliospermum and the habitat M-I for Sida. Piper and
Naravelia did not flower in the forest whereas in the remaining species, flowering
occurred during October-January. Among the six species, Barleria and Naravelia
recorded maximum regeneration- and forest fire was not a limiting factor for the
regeneration of these species.
In the domestic environment, all the species grew flowered and seeded
well with a strictly linear growth pattern upto January. The plant habit changed in
the domestic environment in all the species. Except Naravelia all the species
recorded higher biological and economic yields in the domestic environment.
Phytoconstituents of Desmodium velutinum, Barleria prattensis and
Naravelia zeylanica were reported for the first time.
The nature and content of the primary and secondary metabolites of all
the species varied with the change of habitat.
The study indicated the possibility of cultivating these species by provid-
ing conditions similar to that of the natural habitat; thereby assuring the quality of
the drug.
Necessity for regulating the collection of medicinal plants from the
Peechi forests was also highlighted.