Systematic studies and landscape application of ornamental plants in Thiruvananthapuram district, Kerala
The PhD thesis, “Systematic studies and landscape application of ornamental plants in Thiruvananthapuram district, Kerala” deals with the taxonomic and gardening potential of the ornamental plants in the District. Even though, the study is technically restricted in a single district due to the limits of being an academic course, in effect it covers much wider range as the garden flora is almost the same all over Kerala or even further. Identification keys reaching to all the 470 species, their nomenclature with reference to publications, previous reports from elsewhere in and outside the country, detailed characterization based on floristic studies of original specimens etc are included in the taxonomic part. As the conventional floristic studies concentrates mainly on natural flora, about 90% (420 / 470) of the plants reported in the study are new to the district. The thesis also has a horticultural part that evaluates the potential of each plant to be used as a landscaping component. Based on their habit and the elements form, color, texture or pattern, the aesthetic and functional role of the plants in landscape were evaluated. Thus they were assessed for the aesthetic roles such as specimen plant, structural plant, ground cover, edge plant, bedding plant, avenue plant, hedge/topiary plant, scent generating plant, etc as well as for the functional roles like screen plant, transition/softening plant etc. The plants were searched for the region of their origin and evaluated the influence of exotic species in our garden flora. Among the 470 species, only136 (28.9 %) are native out of which only 9 are endemic. Scope of garden escapes among the 71% exotic species was also studied. In total, the study is an attempt integrating disciplines of taxonomy, ecology and horticulture to identify and classify the garden plants, to evaluate their potential as a component in garden landscaping, to assess the influence of the exotic species in the garden flora and probable impacts in the general flora.