María S. Ferrucci

Cytotaxonomy of Sapindaceae with special reference to the tribe Paullinieae

, 1995;Ferrucci and Solis Neffa, 1997; Solis Neffa and Ferrucci,1997, 1998; Lombello and Forni-Martins, 1998), and chro-mosome numbers of 127 species have been reported andthe complete karyotypes of 35 species are known, althoughonly a few papers give information on interphase nucleusstructure, chromosome condensing behavior, Giemsa C-banding, NOR-banding and nucleolus counts (Eichhorn andFranquet, 1936; Guervin, 1961; Hemmer and Morawetz,1990; Nogueira

Anatomical and developmental studies on floral nectaries in Cardiospermum species: an approach to the evolutionary trend in Paullinieae

Floral nectaries are a widespread trait in the Sapindaceae. However, until now only a few data on nectaries and their evolutionary shifts are available for most taxa. This research focuses on the anatomy and development of floral nectaries in two endemic species, Cardiospermum heringeri and C. integerrimum. The nectary consists of two horn-like lobes, located at the base of the androgynophore. Anatomically, it is characterized by three components: uniseriate epidermis, sub-epidermal secretory tissue and vascular tissue. The epidermis contains many nectarostomata involved in the exudation process. The secretory parenchyma is composed of small thin-walled cells, relatively lightly stained, and idioblasts containing oxalate druses. Vascular tissue supplying the nectary consists exclusively of phloem. From an early stage of development, the nectary lobes in both species are associated with the base of the posterior petals, but each organ originates independently of one another. These results plus additional morphological observations of nectary lobes in some species of Cardiospermum, Serjania, Paullinia and Urvillea were analyzed within the framework of phylogenetic knowledge.

Cardiospermum cristobaliae (Sapindaceae, Paullinieae), una nueva especie de Minas Gerais, Brasil

ResumenLa especie nueva Cardiospermum cristobaliae (Sapindaceae, Paullinieae), de la región norte del estado de Minas Gerais, Brasil, es descrita, ilustrada y comparada con la especie más próxima, C. urvilleoides. Adicionalmente se describen caracteres de epidermis foliar y de polen. Se reporta el número cromosómico somático 2n = 24. La especie nueva pertenece a la sección Cardiospermum, se presenta un cuadro comparativo con la especie afín y una clave de las especies sudamericanas de esta sección.AbstractA new species, Cardiospermum cristobaliae (Sapindaceae, Paullinieae), from northern Minas Gerais, Brazil, is described, illustrated, and compared to its putative closest relative, C. urvilleoides. The new species belongs to section Cardiospermum. Also, characters of the foliar epidermis and pollen grains are described. The somatic chromosome number 2n = 24 is reported. A key to the South American species of the section is provided.

Floral nectaries of Heliocarpus popayanensis and Luehea divaricata (Malvaceae-Grewioideae): structure and ultrastructure

The structure and ultrastructure on floral nectaries of Heliocarpus popayanensis Kunth. and Luehea divaricata Mart (Malvaceae-Grewioideae) were investigated for the first time. The floral nectaries of the analysed species are structured (can be recognised macroscopically and microscopically) and of trichomatic type. Significant morphological differences were observed between the nectaries of perfect and pistillate flowers of H. popayanensis, as well as between nectaries of this species and those of the related species, Triumfetta rhomboidea Jacq. The volume of nectar produced in the perfect and pistillate flowers of H. popayanensis and in the perfect flowers of L. divaricata presents significant differences that could be related to the rewards offered to flower visitors. No differences were observed in ultrastructure features of the glandular trichomes between H. popayanensis and L. divaricata. Nectar accumulation occurs between the wall and the cuticle. The predominant floral visitors in perfect and pistillate flowers of H. popayanensis were bees, and less frequently flies; whereas for L. divaricata were wasps, bumblebees, butterflies and beetles. Our results support the inclusion of each genus in different tribes according to the recent tribal classification based on molecular and morphological data of the subfamily Grewioideae.