Documenting the floral biology and breeding system of species throughout the Rubiaceae family provides data on the number of times heterostyly and dioecy may have evolved in this large family. The objectives of this paper are to quantify (a) whether Chassaliu corallioides, a small tree endemic to L a Rtunion Island in the Indian Ocean, is another example of the evolution of dioecy from distyly and (b) whether reproductive traits linked to male and female function vary over the ecological distribution of this species. Quantification of pollen production and fruit set following controlled and natural pollinations demonstrate that this species is dioecious. Male flowers have longer corolla tubes than female flowers. Female flowers have long styles with stigmas placed above the anthers whereas males have short styles with stigmas placed below the anthers. Stigmas and anthers are reciprocally placed in each morph, illustrating that the species is morphologically heterostylous. Both fecundity and flower size are negatively correlated with altitude. In male plants, corollas are shorter and wider and anthers are placed closer to the mouth of the corolla tube with increasing altitude. Male plants flowered more often than female plants, the likely cause of the male biased sex ratio in each of the two years studied. The evolution of dioecy in relation to the island biogeography of the region and the diversification of the genus Chmsalia is discussed.
In the extrafloral nectary of the broad bean there is evidence of two fundamental types of cells: one with dense hyaloplasm, well developed ergastoplasm and golgi apparatus, all features of glandular cells, and another with opposite features. The cells of the head of the secretory hairs and those of the subjacent epidermis which are not prolonged with such a hair are of the first type. The epidermal cells prolonged with a hair and the pedicellar cell of this hair are of the second type. Moreover, the companion cells of the subjacent conducting bundle look like cells of the first type, especially those of the head of the secretory hairs owing to their numerous wall protuberances. Cells of the second type are presumably involved in transit processes between phloem and trichome, and cells of the first type in excretory processes.
In the extrafloral nectary of broad bean and in the companion cells of its subjacent conducting bundle, there is evidence of the presence of acid phosphatase around and in the plasmalemma. This evidence suggests an active transport of sugars during their translocation from cell to cell and their excretion. Endoplasmic reticulum and Golgi apparatus are often stained by the lead phosphate reaction, a result showing the presence of acid phosphatase in these organelles. From the intensity and localization of this reaction three types of nectary cells can be distinguished.
In the glandular cells of the petiolary glands of Impatiens holstii, acid phosphatase is present in endoplasmic reticulum, Golgi apparatus, cytosomes, vacuoles, some nuclei and mitochondria. Only a few plasmalemma and cell walls are lightly marked except in the region of sieve tubes and "transfer cells" where there are heavy deposits of lead phosphate. We note two fundamental types of vacuoles: autophagic vacuoles which are heavily marked and others which have lead deposits only in their tonoplast.The possible role of the enzyme in secretory processes is discussed.
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