Search results for "Floral biology"
showing 5 items of 5 documents
Christian Konrad Sprengel’s Theory of the Flower: The Cradle of Floral Ecology
1996
As the plant taxonomist Karl Suessenguth once wrote, there are two kinds of discoveries: Detecting a thing nobody has seen before, or thinking what no one has thought before about something that everybody sees. A discovery of the second kind, and one of great moments in our science, was Sprengel’s theory of the flower. This theory clearly expressed for the first time the notion that flowers are designed for the transmission of pollen by foreign vectors, that is, animals or wind, and they can be understood only from this perspective.
POLLEN MORPHOLOGY AND REPRODUCTIVE PERFORMANCES IN OPUNTIA FICUS-INDICA (L.) MILL.
2015
The fruits of Opuntia ficus-indica (L.) Mill., the most worldwide cultivated species of Cactaceae family, contain viable seeds (100-250) of large size. This characteristic influences the commercial quality of the fruit. The study of floral biology in Opuntia allows to understand the behaviour of the plant during reproductive phase and perhaps to distinguish clones with different fruits behaviour (with seed and seedless). The study resulted in a palynological characterization by optical and scanning microscopy (SEM), followed by a qualitative analysis on the male line with pollen viability and in vitro germination tests, in addition to a pollen-pistil interaction survey. The plant material c…
New Insights into the Functional Morphology of the Lever Mechanism of Salvia pratensis (Lamiaceae)
2007
† Background and Aims The functional morphology of Salvia pratensis flowers was re-investigated, after new insights revealed that pollen dispensing is one of the main functions of the staminal lever. In particular, no detailed information was available regarding the process of pollen transfer and the forces arising between the pollen-bearing thecae and the pollinating bee’s body. The assumption was made that these forces play a significant role in pollen dispensing. † Methods The functional morphology of S. pratensis flowers and the interaction between flowers and bees (Apis mellifera) were studied by reconstructing stress and strains by using qualitative and semi-quantitative theoretical a…
Floral Diversity and Pollen Transfer Mechanisms in Bird-pollinated Salvia Species
2007
† Background and Aims Bird-pollinated (ornithophilous) Salvia species (sages) transfer pollen either by means of a staminal lever mechanism or by immovable stamens. As the distribution of the two modes within the genus is not known, we present a survey of all ornithophilous sages. The main focus is given to floral diversity especially with respect to functional lever morphology. Thereby the hypothesis is tested that, due to a pollinator shift from bees to birds, the lever mechanism became unnecessary. † Methods To get a general idea about the diversity of pollen transfer mechanisms, 186 ornithophilous Salvia species were classified according to the functional morphology of the stamen and th…
Bilabiate Flowers: The Ultimate Response to Bees?
2007
† Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. † Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combi…