منابع مشابه
The evolution of floral nectaries in Disa (Orchidaceae: Disinae): recapitulation or diversifying innovation?
BACKGROUND AND AIMS The Orchidaceae have a history of recurring convergent evolution in floral function as nectar production has evolved repeatedly from an ancestral nectarless state. However, orchids exhibit considerable diversity in nectary type, position and morphology, indicating that this convergence arose from alternative adaptive solutions. Using the genus Disa, this study asks whether r...
متن کاملDiversity and distribution of extra-floral nectaries in the cerrado savanna vegetation of Brazil
Aim. Throughout evolutionary history, plants and animals have evolved alongside one another. This is especially apparent when considering mutualistic relationships such as between plants with extra-floral nectaries (EFNs, glands on leaves or stems that secrete nectar) and the ants that visit them. Ants are attracted by the nectar and then protect the plant against destructive herbivores. The di...
متن کاملEvolution of floral symmetry
Flowers can be classified into two basic types according to their symmetry: regular flowers have more than one plane of symmetry and irregular flowers have only a single plane of symmetry. The irregular condition is thought to have evolved many times independently from the regular one: most commonly through the appearance of asymmetry along the dorso-ventral axis of the flower. In most cases, t...
متن کاملUltrastructure and post-floral secretion of the pericarpial nectaries of Erythrina speciosa (Fabaceae).
BACKGROUND AND AIMS The occurrence of nectaries in fruits is restricted to a minority of plant families and consistent reports of their occurrence are not found associated with Fabaceae, mainly showing cellular details. The present study aims to describe the anatomical organization and ultrastructure of the pericarpial nectaries (PNs) in Erythrina speciosa, a bird-pollinated species, discussing...
متن کاملThe evolution of floral gigantism.
Flowers exhibit tremendous variation in size (>1000-fold), ranging from less than a millimeter to nearly a meter in diameter. Numerous studies have established the importance of increased floral size in species that exhibit relatively normal-sized flowers, but few studies have examined the evolution of floral size increase in species with extremely large flowers or flower-like inflorescences (c...
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ژورنال
عنوان ژورنال: Annals of the Missouri Botanical Garden
سال: 2003
ISSN: 0026-6493
DOI: 10.2307/3298546