Tagged: Apocynaceae


Apocynaceae

The diversity and evolution of pollination systems in the Apocynaceae

Interactions between flowering plants and their pollinators are known to be responsible for part of the tremendous diversity of the angiosperms, currently thought to number at least 350,000 species. Using a new database of pollinators of the large, globally distributed family Apocynaceae (>5300 species) Ollerton et al. explore how different types of pollination system (bird, bee, moth, fly, etc.) are distributed across the evolutionary tree of the family; how those pollination systems have evolved over time; and how they vary biogeographically. Earlier diverging clades are characterized by a narrower range of pollination systems. Within Apocynaceae, interactions with pollinators are highly...

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A map of genetic distribution

Genetic differentiation among varieties of a Neotropical savanna tree

The Neotropical savanna fruiting tree species, Hancornia speciosa (Apocynaceae) has high social and economic importance in Brazil. Originally classified as six botanical varieties, more recently only two have been recognised. In a study of the genetic diversity and structure of over 750 individuals from 28 populations Collevatti et al. found five distinct genetic groups, supporting the older classification. Although there was evidence of high historical gene flow between populations in the central geographical range, genetic differentiation was associated with geographical distance between populations. Although genetic variation was not apparently linked to climatic or soil conditions, areas of higher historical climatic...

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Butterflies visit more frequently, but bees are better pollinators: the importance of mouthpart dimensions in effective pollen removal and deposition

Pollination studies often use visitation frequency of potential pollinators as an indicator of their importance, but this is only one component and may not reflect actual pollen-transfer rates. In a recent study published in AoB PLANTS, Barrios Roque et al. used new approaches to understand the pollination biology of the pineland golden trumpet, Angadenia berteroi, a charismatic wildflower species that is native to south Florida pine rocklands, and ubiquitous in this imperiled, fire-successional habitat. In this system, the width of the proboscis of the pollinators was correlated with pollen transfer efficiency, and long­tongued bees were the most effective pollinators, though...

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Different potential for synorganization of floral organs in different phyllotaxis patterns.

Development and evolution of extremely complex flowers

The two very species-rich families Apocynaceae and Orchidaceae contain the most complex flowers in the angiosperms. Although they are not related they show a number of amazing convergent similarities in flower structure. Endress reviews and compares development and evolution of this complexity in both families. It has arisen by progressive synorganization of the basic floral organs, especially androecium and gynoecium, and partly also by the emergence of novel floral parts. As a result the flowers look puzzling and the basic organs can no longer be easily recognized at first sight.

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