Vegetative and floral morphology of Jatropha species in the Niger Delta

Abstract

The morphology (vegetative and floral) of Jatropha L. species (Jatropha curcas L., Jatropha gossypifolia L., Jatropha multifida L. and Jatropha podagrica Hook) in parts of the Niger Delta was investigated. The study aimed at establishing taxonomic affinities and differences between these species based on their leaves, inflorescences, flowers, fruits and seed characteristics. Visual observations, measurements and photographs of relevant organs of wild and ornamental collections of the four species were taken. Results obtained showed that the four species differ distinctively in leaf outline, leaf length, leaf base, margin and texture with the glandular leaf margin of J. gossypifolia and incised lobes of J. multifida being diagnostic and asserting their statuses as taxonomic species. Leaf length varied from 7.01±0.90 cm in J. gossypifolia to 24.75±1.18 cm in J. podagrica. The distinct yellowish-green flower colour of J. curcas distinguishes it from other species which possess different shades of red colour. Variation was observed in fruit shape (ellipsoid and tear-drop shapes) of J. curcas showing that intraspecific morphological or ecological types exist within this species. However, similarities were observed in leaf venation which is actinodromous and basal in all species and in floral arrangement which is cymose. These and other features confirm the relatedness of the species. © 2012 Academic Journals Inc.