Temporal dioecism, melittophily and anemochory of Wendlandia glabrata (Rubiaceae)

A J Solomon Raju ,K V V Ramana

doi:10.4038/tapro.v6i2.7189

Abstract

Wendlandia glabrata is a massive bloomer during February–March. Floral characteristics such as diurnal anthesis, white coloured, odorless, tubular flowers with deep seated sucrose-rich nectar conform to psychophily. Nectar is a source of essential and non-essential amino acids for butterflies, inconsistent foragers due to nectar traces in open flowers. This suggests a breakdown of psychophilous pollination. Honey bees consistently collect only pollen. Flies are also inconsistent nectar foragers. Therefore, W. glabrata with psychophilous pollination syndrome is actually melittophilous, and the flowers exhibit Secondary Pollen Presentation (SPP). The flowers are morphologically hermaphroditic but functionally temporally dioecious which promotes outcrossing. Natural fruit and seed set rates are attributed to pollen robbery by honey bees. Anemochory is effective to dispersal of seeds. In situ seedling establishment rate is low due to habit, seasonal herbaceous vegetation and space limitation. Therefore, we recommend that seedlings be raised in nurseries and transplanted to rebuild populations of W. glabrata . DOI: http://dx.doi.org/10.4038/tapro.v6i2.7189 TAPROBANICA, 2014. Vol. 06, No. 02: pp. 83-89 pls. 4-6.

Highlights

The Rubiaceae Juss. are a large family distributed over the temperate and tropical regions of the world
Robbrecht (1988) pointed out the presence of three reproductive strategies common in Rubiaceae: distyly, morphologically characterized by the presence of two inter-compatible floral morphs, which is generally observed in species of Rubioideae Bremek. ex Verdc. (Barrett, 1992); stylar pollen presentation involving protandry and pollen presentation in the style which is generally recorded in Dialypetalanthoideae Reveal; and the occurrence of unisexual flowers in certain species almost restricted to Rubieae Baill. and TEMPORAL DIOECISM, MELITTOPHILY AND ANEMOCHORY OF Wendlandia glabrata
Puff et al (1996) reported that Secondary Pollen Presentation (SPP) occurs widely among all subfamilies. These authors have recognized four types of SPP based on the pollen presenting area and receptive surface of style and stigma

Summary

Introduction

The Rubiaceae Juss. are a large family distributed over the temperate and tropical regions of the world. Are a large family distributed over the temperate and tropical regions of the world It shows a wide spectrum of floral mechanisms characterized by different types of gynoecium and androecium organization. Bir Bahadur (1968) documented three types of flower sex in the Rubiaceae – heterostyly, dioecy, and hermaphroditic or gynodioecy. He mentioned that 91 genera with 416 species are dimorphic and heterostylous. Puff et al (1996) reported that Secondary Pollen Presentation (SPP) occurs widely among all subfamilies These authors have recognized four types of SPP based on the pollen presenting area and receptive surface of style and stigma. Pollen deposition occurs on the outer surface of the stigma while in the fourth type, it occurs exclusively, largely or partly on the receptive surface of the stigma

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Conclusion