The great taxonomic diversity of the Orchidaceae is often attributed to adaptive radiation for
specific pollinators driven by selection for outcrossing. However, when one looks beyond the …

Pollen accumulates starch reserves during development and the final stage of ripening.
Before the anther opens, starch is totally or partially converted to pectins, glucose, fructose …

Cohesive masses of pollen known as pollinia have evolved independently in two plant
families—Orchidaceae and Asclepiadaceae. Yet, the bilateral symmetry of orchids has …

In this year celebrating the bicentenary of the birth of Darwin and the sesquicentennial of the
publication of Darwin's On the Origin of Species, the present paper aims to assess the …

We studied the floral biology of 12 populations of five rupicolousPleurothallis (Orchidaceae)
species occurring in campo rupestre vegetation at nine localities in Brazil. All of these …

Intra-and interspecific experimental pollinations were made to determine the mating systems
and the interspecific crossing potential in individuals from 24 populations of five Pleurothallis …

The problem of the water content of pollen is reconsidered, especially the distinction
between “partially hydrated pollen”(PH pollen), pollen with a water content greater than …

The main morphological, cytological and physiological characters of ripe pollen are
described, compared, analysed and discussed individually, in multiple combinations and in …

The various pollen dispersal units (PDU) found in orchids are discussed together with
possible evolutionary trends and the consequences for germination and fertilization. Orchids …

Orchidaceous are the most diverse group of plants with estimate of more than 25000
species (Dressler, 1993). Distribution and abundance of orchids vary between continents …