Gynoecium

 We describe a new method to determine stigma receptivity by using a Peroxtesmo esterase indicator paper liquid (one paper+1 ml water). This technique enables the researcher to check instantly the receptivity of various types of stigmas and to locate the receptive area.

The monogeneric Kirkiaceae (Sapindales) were formerly placed as Kirkioideae in Simaroubaceae. However, recent molecular phylogenetic studies indicate that they are not in Simaroubaceae and they appear to be sister to the clade of Anacardiaceae plus Burseraceae. Such affinity was never considered or discussed since the first description of Kirkia. The present study is the first detailed analysis of the floral structure of a representative of Kirkiaceae and the first comparison with other sapindalean families, especially Anacardiaceae and Burseraceae. Floral structure of Kirkia wilmsii was studied using transversal and longitudinal microtome section series, scanning electron microscopy and light microscopy. The flowers of Kirkia wilmsii are morphologically bisexual but functionally unisexual. They are polysymmetric, isomerous (tetramerous) and haplostemonous. The ovary is syncarpous and entirely synascidiate. The floral apex forms a hemispherical protrusion on top of the ovary. The st...

In this study, some morphological characters, anatomical features and chromosome numbers of alpine Lamium cymbalariifolium Boiss. (Lamiaceae) endemic to Turkey are firstly described in detail. Lamium cymbalariifolium is an east mediterrenean element growing on north-facing limestone screes at an altitude of 2100-2280m in the Southwest Anatolia. The investigated species is closely allied to L. microphyllum and L. sandrasicum which are other alpine endemic species to Turkey. Taxonomically significant characters for L. cymbalariifolium are tried to be pointed out. Morphologically, the corolla tube length, the upper lip length, lobe length of the upper lip, the lower lip length and lobe length of the lower lip, the length of pistil, filament, anther and the seed dimensions of the species are firstly reported in the present study. Anatomically, spring and autumn woods of the root, which are forming annual rings are clearly distinguishable. Stem has a thin collenchymatous layer at the cor...

In this study, some morphological characters, anatomical features and chromosome numbers of alpine Lamium cymbalariifolium Boiss. (Lamiaceae) endemic to Turkey are firstly described in detail. Lamium cymbalariifolium is an east mediterrenean element growing on north-facing limestone screes at an altitude of 2100-2280m in the Southwest Anatolia. The investigated species is closely allied to L. microphyllum and L. sandrasicum which are other alpine endemic species to Turkey. Taxonomically significant characters for L. cymbalariifolium are tried to be pointed out. Morphologically, the corolla tube length, the upper lip length, lobe length of the upper lip, the lower lip length and lobe length of the lower lip, the length of pistil, filament, anther and the seed dimensions of the species are firstly reported in the present study. Anatomically, spring and autumn woods of the root, which are forming annual rings are clearly distinguishable. Stem has a thin collenchymatous layer at the cor...

In this study, the morphological and anatomical features of endemic Lamium moschatum Miller var. rhodium (Gand.) R. Mill (Lamiaceae) are described in detail. Lamium moschatum var. rhodium has an annual taproot. The stem is erect and clearly quadrangular. The leaves are broadly ovate to cordate-ovate or nearly suborbicular in shape. Inflorescense is verticillate cyme. The corolla is white and the tube is curved and bears an annulus inside, near the base. Cross-sections of the root, stem, petiole, leaf, calyx, corolla and generative organs were examined and the anatomical features of the taxon are discussed. Furthermore, glandular hairs distributed on the plant taxon are shown. In karyological research, chromosome numbers were determined as 2n = 18. The results are presented with photographs and tables.

Sex determination in maize is controlled by a developmental cascade leading to the formation of unisexual florets derived from an initially bisexual floral meristem. Abortion of pistil primordia in staminate florets is controlled by a tasselseed-mediated cell death ...

Vegetal material from papaya (Carica pa- paya L.) 'Maradol' variety and 'Tainung-1' hybrid were collected from two plantations and taken to the Plant Physiology laboratory to analyse their flower and seed morphology. Descriptions were made of the three types of flowers (female, hermaphrodite and staminate) and the seeds' external (shape, size, hilum, micropyle, funicle, raphe and testa) and internal char- acteristics (testa, endosperm and embryo). The main morphological conclusion was that the flowers and seeds from the two types evaluated showed similar characteristics; the descriptions given in this paper are thus general for them.

Based on the assumptions that pollen tube length is predetermined by provisions in the pollen and that it is a function of pistil length, I hypothesise that species with longer pistils will have larger pollen grains than species with shorter pistils, and that pistil length and pollen size will be positively correlated in a linear manner. To test this hypothesis, the relationship between pollen grain volume and pistil length was compared in 43 Asteraceae species from Argentina. A positive linear correlation was found between pollen volume and pistil length. This correlation remained significant even after potential effects of phylogenetic relatedness were removed. The maintenance of this correlation suggests that in Asteraceae the association between pistil length and pollen volume may reflect a functional rather than a phyletic relationship. In addition, the pistil length: pollen volume ratio (PPR) was analysed in relation to the phylogenetic position of the species. High values of PPR would imply a reduction of the male gametophyte in relation to the minimal volume that a pollen grain must have to grow and fertilise an ovule. Thus, the general pattern of pollen volume reduction in relation to pistil length previously found among many angiosperm families will be also present within a family, i.e., PPR values of derived Asteraceae would be higher than those of basal species. Results indicated that reduction of pollen volume in derived Asteraceae was three times greater than the concomitant shortening of pistil length. Consequently, PPR increased with the phylogenetic position of the taxa. This work supports the correlation between pistil and pollen characters previously found for other plant families and confirms the influence of post-pollination processes on pollen size evolution.

The inflorescence of Philodendron constitutes an interesting morphological model to analyse the phenomenon of homeosis quantitatively at the floral level. The specific goals of this study were (1) to characterize and quantify the range of homeotic transformation in Philodendron billietiae, and (2) to test the hypothesis that the nature of flowers surrounding atypical bisexual flowers (ABFs) channel the morphological potentialities of atypical bisexual flowers. Inflorescences of P. billietiae at different stages of development were observed using SEM. The number of appendices in male, female and sterile flowers were counted on 11 young inflorescences (5-6 flowers per inflorescence). The number of staminodes and carpels on ABFs were counted on 19 inflorescences (n = 143). These data were used for regression and ANOVA analyses. There was an average of 4.1 stamens per male flower, 9.8 carpels per female flower and 6.8 staminodes per sterile male flower. There was an average of 7.3 flora...

The aim of this contribution was to analyze the morpho-anatomicaloral structure of Epiphyllum phyllanthus (L.) Haw., a widely distributed species across South America, occurring in humid forests as an epiphyte. Flowers and � ower buds were collected in Maringa, Parana State, Brazil, � xed, processed, and analyzed under light microscope and scanning electron microscope. Theower is sessile and epigynous with a well-developed hypanthium. Allower whorls have uniseriate epidermis. Secretory cavities containing mucilage and calcium oxalate crystals occur throughout theoral parenchymatous tissue. The androecium has many stamens with tetrasporangiate and bithecal anthers. The wall of the young anther is formed by epidermis, endothecium, a middle layer, and binucleate secretory tapetum that eventually becomes uninucleate. The gynoecium is syncarpous with 9-10 carpels, pluriovulate, and with parietal placentation. The ovary has inverted vascular bundles in a similar pattern as in Pereskia. Th...

The aim of this contribution was to analyze the morpho-anatomical fl oral structure of Epiphyllum phyllanthus (L.) Haw., a widely distributed species across South America, occurring in humid forests as an epiphyte. Flowers and fl ower buds were collected in Maringá, Paraná State, Brazil, fi xed, processed, and analyzed under light microscope and scanning electron microscope. The fl ower is sessile and epigynous with a well-developed hypanthium. All fl ower whorls have uniseriate epidermis. Secretory cavities containing mucilage and calcium oxalate crystals occur throughout the floral parenchymatous tissue. The androecium has many stamens with tetrasporangiate and bithecal anthers. The wall of the young anther is formed by epidermis, endothecium, a middle layer, and binucleate secretory tapetum that eventually becomes uninucleate. The gynoecium is syncarpous with 9-10 carpels, pluriovulate, and with parietal placentation. The ovary has inverted vascular bundles in a similar pattern a...

Based on the assumptions that pollen tube length is predetermined by provisions in the pollen and that it is a function of pistil length, I hypothesise that species with longer pistils will have larger pollen grains than species with shorter pistils, and that pistil length and pollen size will be positively correlated in a linear manner. To test this hypothesis, the relationship between pollen grain volume and pistil length was compared in 43 Asteraceae species from Argentina. A positive linear correlation was found between pollen volume and pistil length. This correlation remained significant even after potential effects of phylogenetic relatedness were removed. The maintenance of this correlation suggests that in Asteraceae the association between pistil length and pollen volume may reflect a functional rather than a phyletic relationship. In addition, the pistil length: pollen volume ratio (PPR) was analysed in relation to the phylogenetic position of the species. High values of PPR would imply a reduction of the male gametophyte in relation to the minimal volume that a pollen grain must have to grow and fertilise an ovule. Thus, the general pattern of pollen volume reduction in relation to pistil length previously found among many angiosperm families will be also present within a family, i.e., PPR values of derived Asteraceae would be higher than those of basal species. Results indicated that reduction of pollen volume in derived Asteraceae was three times greater than the concomitant shortening of pistil length. Consequently, PPR increased with the phylogenetic position of the taxa. This work supports the correlation between pistil and pollen characters previously found for other plant families and confirms the influence of post-pollination processes on pollen size evolution.