On the reproductive ecology of Premna latifolia L. and Premna tomentosa Willd. (Lamiaceae)

Abstract

Premna latifolia and Premna tomentosa shed their foliage during winter but produce foliage at different periods to avoid competition for nutrients, P. latifolia during the dry season while P. tomentosa during the wet season. Flowering also occurs at different seasons, P. latifolia during the wet season and P. tomentosa during the dry season. The flowering period of P. latifolia is comparatively longer than P. tomentosa; however, both of them display profuse flowering for 2–3 weeks only. The flowers are of gullet type, weakly bilabiate, and the stamens and stigma are situated near the upper corolla lip and are dichogamous, herkogamous and facultatively xenogamous in both species. In P. latifolia, the pollinators are wasps and butterflies while in P. tomentosa, in addition to wasps and butterflies, the bees and flies are also pollinators. Camponotus ants rob the nectar of P. latifolia by removing the entire corolla together with stamens and sometimes also with the style and stigma. Both the species display ornithochory, anthropochory and anemochory. The seeds germinate during wet season in both the species irrespective of their time of dispersal but their continued growth depends on the soil nutrient and moisture environment.

Keywords

• lamiaceae
• pollination
• premna latifolia
• premna tomentosa
• reproductive ecology.