Handbook of palynology

Plant Breeding Systems.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1096-0031.2008.00212.x

Plant Systematics: A Phylogenetic Approach

Nectar production and presentation

The construction of classifications, as well as the understanding of biological diversity, depends upon a careful comparison of attributes of the organisms studied (Stuessy, 1990). It is widely known that data from diverse sources showing differences from taxon to taxon are of systematic significance. During the 20th century, systematists have emphasized that their discipline involves a synthesis of all knowledge (Stevens, 1994) or, in other words, the variation of as many relevant characters as possible should be incorporated into the natural system to be constructed. The extent to which particular characters are constant or labile will determine their usefulness to systematics. In general, more conservative characters will be valuable in defining families and orders, whereas more labile characters may be useful at the generic and specific levels (Webb, 1984). There is no doubt that floral characters are among the most used in the classification of flowering plants. At the same time, they constitute essential features in diagnostic keys to taxa in both taxonomic treatments and Floras (Cronquist, 1981, 1988).

A systematic survey of floral nectaries

Ovule and female gametophyte in representatives of Nymphaea subgenus Hydrocallis and Victoria (Nymphaeaceae; Nymphaeoideae)

Cabomba Aubl. is a genus that presents a range of features that have made it to be considered a potential genetic model for studies of early angiosperm evolution. Therefore, any study that expands our knowledge of this genus is potentially useful for the understanding of the evolution of early angiosperms. This paper reports the study of the anatomy and the ultrastructure of the stigma and the style of Cabomba caroliniana Gray during the 2 days of anthesis using bright-field microscope, fluorescence microscope and transmission electron microscope. The stigma is dry and has pluricellular papillae. The style is hollow with a central canal coated by an epithelium. The papillae have fewer organelles than those typical of glandular cells, and they are covered by a cuticle that is broken when pollen germinates. The ultrastructure of epithelial cells indicates that the cells lining the canal are secretory. The canal is filled with a fibrillar and granular substance. The pollen tubes grow inside the canal through this substance. The results are discussed in the context of what is known for other species of angiosperms.

https://link.springer.com/content/pdf/10.1007%2Fs00709-015-0799-0.pdf

Ultrastructure of the stigma and style of Cabomba caroliniana Gray (Cabombaceae)

The ultrastructure of the stigmas and styles of Colletia paradoxa, Colletia spinosissima, and Discaria americana was studied by transmission electron microscopy before and during anthesis. The purpose of the study was to contribute a full description of possible interactions between the male gametophyte and the sporophytic tissues of the stigma and the style. Ultrastructure changes in the stigmatic papillae and epithelial and sub-epithelial cells of the stylar channels in relation to pollen tube growth are discussed and compared between species. New pollen tube pathways are described for hollow styles.

Structure of the stigma and style in Colletia and Discaria (Rhamnaceae: Colletieae)

Plant resources foraged by Polybia scutellaris were identified by analysing the pollen content of 14 nests in Magdalena (Buenos Aires Province, Argentina). Six nests were inhabited at the time of collection. The palynological analysis indicated that the wasps visited 33 different taxa of flowering plants during the active cycle of the colonies. Flowers visited by the wasps belonged to both native and exotic plants located close to the nests. The variety of resources foraged by P. scutellaris characterises this species as a generalist flower visitor.

https://www.tandfonline.com/doi/pdf/10.1080/00173134.2010.525663

Pollen content accumulated in nests of Polybia scutellaris (Hymenoptera, Vespidae)

We report a detailed study of the development and morphology of pollen in four species of the genus Pterocactus (Cactaceae), carried out by using LM and SEM. The anther is tetrasporangiate, its wall consists of epidermis, endothecium, one middle layer and a binucleate secretory tapetum. Microspore tetrads are tetrahedrical and pollen grains are shed at bicellular stage. Pollen grains are pantoporate, with a perforate tectum and supratectate spinules.

Beatriz G. Galati

Papers

Ovule and female gametophyte in representatives of Nymphaea subgenus Hydrocallis and Victoria (Nymphaeaceae; Nymphaeoideae)

Ultrastructure of the stigma and style of Cabomba caroliniana Gray (Cabombaceae)

Structure of the stigma and style in Colletia and Discaria (Rhamnaceae: Colletieae)

Pollen content accumulated in nests of Polybia scutellaris (Hymenoptera, Vespidae)

Pollen Development and Morphology in four Species of Pterocactus (Cactaceae)