The structure and ultrastructure on floral nectaries of Heliocarpus popayanensis Kunth. Luehea divaricata Mart (Malvaceae-Grewioideae) were investigated for the first time. analysed species are structured (can be recognised macroscopically microscopically) trichomatic type. Significant morphological differences observed between perfect pistillate flowers H. popayanensis, as well this those related species, Triumfetta rhomboidea Jacq. volume nectar produced in L. presents significant that...

The aim of this study was to analyse the pollen morphological diversity among 19 species Adesmieae and Aeschynomeneae tribes with purpose evaluating their importance for taxonomical delimitation Argentinean systematic significance. Observations measurements were performed on acetolysed grains. samples examined under light scanning electron microscopes. Principal component analysis (PCA) conglomerate quantitative variables. tribe is stenopalynous while eurypalynous; grains are 3-colporate,...

The pollen grain morphology of Jacaratia corumbensis Kuntze, J. spinosa (Aubl.) A.DC., Vasconcellea quercifolia A. St.-Hil., and Carica papaya L. from Argentine samples were examined for the first time, using light scanning electron microscopes. Observations measurements performed on acetolyzed grains. Principal-components analysis was quantitative morphological variables. Pollen grains tri-colporate with lalongate endoaperture, oblate spheroidal to prolate, medium, exine bireticulate or...

The pollen of Cliococca selaginoides (Lam.) C. M. Rogers & Mildner and eight Linum L. species from Argentina were examined using light scanning electron microscopy. Both genera share grains which are 3-zonocolpate, isopolar, radiosymmetric, spheroidal medium to large in size. sculptural elements the exine gemmae or clavae, allow be distinguished characterised. In Bad., is exclusively gemmate whereas clavate (except catharticum whose has only apically microechinate). statistical analyses...

We report a detailed study of the pollen wall structure in Linum burkartii and L. usitatissimum (Linaceae). This was carried out using scanning electron microscopy (SEM) transmission (TEM). Results confirm that exine species studied is formed by: ectexine constituted by clavae, gemmae, loose basal layer, thin endexine fibrilar intine. These observations constitute first on ultrastructure Linaceae characterizes here expands palynological knowledge this family.

Anther development, microsporogenesis and microgametogenesis of six species the genera Corchorus, Heliocarpus, Luehea Triumfetta were analysed. The found to share following characters: ontogeny anther wall basic type; simultaneous microsporogenesis, resulting mainly in tetrahedral tetrads; secretory tapetum pollen grains shed at bicellular stage. Moreover, characters that differentiate them are: presence uninucleate tapetal cells Heliocarpus Triumfetta; binucleate Corchorus multinucleate...

Monoecious species are common within Sapindaceae, and among them a large variation in sexual expression has been reported. In this work we evaluate the expression, phenology, floral biology, mating system eight to sixteen individuals of duodichogamous Koelreuteria elegans (Seem.) A.C. Sm. subsp. formosana (Hayata) F.G. Mey. Results from our study show that all exhibited pattern flowering characterised by two cycles pistillate flowers with an intervening one staminate flowers. The...

The aim of this paper is to investigate the ultrastructural events that occur during pollen grains development, with emphasis in grain wall and tapetum ontogeny Ziziphus jujuba, Z. mucronata, Paliurus spina-christi (Paliureae) Gouania ulmifolia (Gouanieae). Anthers at different developmental stages were processed according classic techniques for transmission electron microscopy. Differences number endothecium layers tapetal cell nuclei found. Tapetal cells present an anastomosing tubular...

This is the first embryological report of Grewioideae subfamily, which meant to contribute characterisation genera Corchorus, Luehea and Triumfetta. Ovule female gametophyte development in C. argutus, L. divaricata T. semitriloba was analysed. The ovules all species are anatropous, bitegmic crassinucellate mixed type. micropyle studied formed by outer integument (exostome). ovule differs from those other two because chalazal tissue expands forming a cap, gives rise wing seed. All present one...

Triumfetta rhomboidea Jacq. se cita por primera vez para Paraguay Oriental y sur de Brasil. Esta especie describe e ilustra, menciona su distribución geográfica en América. Se la compara con T. semitriloba Jacq., más afín.