Floral biology of Eriope blanchetii (Lamiaceae) in coastal sand dunes of NE Brazil

Abstract

The floral biology of the sand dune shrub Eriope blanchetii (Benth) Harley was investigated in a wild population located within an environment protection area near Salvador, NE Brazil. Inflorescence and flower development were monitored, and the reproductive biology was assessed. Inflorescences are terminal panicles, each bearing from one to 38 small, zygomorphic flowers. The duration of an inflorescence is about 2 months, with few new flowers each day. The rewards to visitors are pollen and nectar, the latter being produced in small quantities at the corolla base, near the stylopodium. Three sequential phases of flower development were identified, based on colour changes, pollen and nectar availability, and stigmatic receptivity. Anthesis takes place throughout the day within each plant, and flowers are strongly protandrous. Flowers are short-lived, with individual variations of 7-30 h until corolla abscission. This variation is probably associated to a post-pollinating response, which reduces the length of the female phase and could be advantageous for the economy of nectar production and for increased efficient pollination of the remaining flowers on a plant. The results of the pollination tests (apomixis, spontaneous and manual autogamy, manual cross-pollination, and control) reinforced the role of pollinators for the reproductive success of E. blanchetii , given that the production of fruits from spontaneous pollination is unlikely to be resulting from protandry and given the morphological floral features. Taken together, the morphological and physiological aspects of E. blanchetii floral biology favour cross-pollination, and it is likely that most of the fruits in nature are produced by outcrossing.

A flora apícola de uma área restrita de dunas litorâneas, Abaeté, Salvador, Bahia

“…Estudos de caso realizados com as espécies Eriope blanchetii (Silva et al 2005) a relevância das abelhas como polinizadores. Dentre as plantas visitadas, predominam as espécies com flores pequenas, pouco conspícuas, monoclinas, com simetrias radiais e agrupadas em inflorescências.…”

Structure of bee-flower system in the coastal sand dune of Abaeté, northeastern Brazil

“…Although predominantly melittophilous their flowers are little specialized, opening up for a great spectrum of opportunistic visitors that do not contribute to their reproductive success. The lack of mechanical restrictions imposed by floral morphology, which facilitate the nectar access for the visitors, allied to the previsibility of the resource, would be the responsible factors for the intensive visits of some predominant species (Silva et al 2005).…”

“…For instance, the predominance of species as Cuphea brachiata and Eriope blanchetii, that produce nectar in a constant manner and in low concentration (Silva et al 2005), and of Chamaecrista ramosa, that presents poricide anthers, besides the presence of oil producing species of the families Malphigiaceae and Krameriaceae.…”

“…The floral density has positive effect on the number and on diversity of visitors (Silva et al 2005).…”

Floração, produção de néctar e abelhas visitantes de Eriope blanchetii (Lamiaceae) em dunas costeiras, Nordeste do Brasil

“…As espécies desse gênero são, geralmente, associadas à polinização por abelhas solitárias (HARLEY, 1971;MARTINS, 1995). Os testes de polinização têm indicado baixa produção de frutos por polinização espontânea e a morfologia e a fisiologia das flores de E. blanchetii favorecem a polinização cruzada, sugerindo que a formação de frutos na natureza depende de vetores de pólen (SILVA et al, 2005).…”