Himatanthus bracteatus (A. DC.) Woodson (Apocynaceae): phenology, morphology, and floral biology of a species endemic to the Atlantic Forest¹

Himatanthus bracteatus (A. DC.) Woodson (Apocynaceae): fenologia, morfologia e biologia floral de uma espécie endêmica da Mata Atlântica

ABSTRACT

Janaúba, Himatanthus bracteatus (A. DC.) Woodson is a species native to the Atlantic Forest and restricted to the northeastern and southeastern regions of Brazil, and has potential as ornamental or in the recovery of degraded areas. Considering that the information about its reproductive mechanisms is scarce, this study aimed to describe the aspects of the phenology, morphology, and floral biology of H. bracteatus in an urban remnant of Atlantic Forest in Salvador (State of Bahia). Monthly, from August 2008 to August 2009, we recorded the intensity of the phenophases (flowering, fruiting, and budding), aspects of the morphology, and floral development in 15 adult individuals. Flowers and fruits occurred almost throughout the month; the flowering peak was associated with the rainy season, and the seeds dispersion occurred through the wind. Flowers are white, bisexual, cleistogamous and remain open for more than 24 hours, suggesting a more elaborate pollination process, dependent on nocturnal and diurnal specialist visitors for their reproduction.

Keywords:
floral events; tropical reforestation; janaúba; floral morphology; ornamental potential