POLLINATION ECOLOGY OF THE ANNUAL HERB, HEDYOTIS BRACHIATA (RUBIACEAE)

A.J. Solomon Raju, J. Radhakrishna

Abstract


Hedyotis brachiata presents a phenology that concentrates vegetative growth and reproduction during rainy and winter season. In this study, we investigated floral morphology, floral biology, pollination, pollinators, fruit and seed dispersal aspects.  It is an annual herb that grows in open, sandy soilsIt is distylous, herkogamous and self-compatible. The pin and thrum plants produce high natural fruit and seed set, but it is highest in thrum plants. Autonomous selfing occurs in thrum flowers while it is precluded in pin flowers, however, selfing occurs due to the foraging activity of thrips. The plant is pollinated by honey bees and lycaenid butterflies. Other insects also pollinate the plant but they are occasional foragers. The plant produces multi-seeded capsules which mature within three weeks. Fruit is a non-fleshy erect and cup-like capsule which dehisces septicidally. The seed dispersal modes include anemochory, barochory, ombrochory and hydrochory. The seeds are dormant, germinate and produce new plants seasonally.  Therefore, the study substantiates that this plant is evolved to complete its entire life cycle seasonally.


Keywords


Hedyotis brachiata; distyly; herkogamy; honey bees; lycaenid butterflies: anemochory; barochory; ombrochory and hydrochory

Full Text:

PDF


DOI: http://dx.doi.org/10.4462/annbotrm-13847

Annali di Botanica is published by the Department of Environmental Biology - University La Sapienza of Rome, Italy. The journal is printed by Sapienza Università di Roma - Centro Stampa Università.

ISSN: 2239-3129