Anatomy of the Dicotyledons

For the robust identification of taxonomically complex fern family like Athyriaceae, light and scanning electron microscopy is significance implications. This article present first microscopic investigation of foliar micromorphology of 3 genera and 10 species belonging to Athyriaceae namely, Athyrium, Deparia, and Diplazium were collected from different localities in Malakand Division, Northern Pakistan. In present study we compare foliar micromorphology of all 10 species using standard protocols of light microcopy (LM) and scanning electron microscopy. Qualitative micromorphological variations in shape of epidermal cells, anticlinal wall pattern, stomatal type and shape, stomatal pore shape, guard cells shape, and trichomes types were studied. In addition, some quantitative characters were also studied and data were statistically analyzed in epidermal cell size, stomatal size, stomatal pore size, stomatal density, and stomatal index. The pivotal result of study include; shape of epidermal cell in all species is irregular on both abaxial and adaxial surfaces. The anticlinal walls are sinuous in most of the species but some species have irregular lobed and broadly lobed wall. Leaves are hypostomatic in all studied species. Two main categories of stomatal type were found: polocytic and anomocytic. Unicellular nonglandular trichomes were observed in only one species Athyrium mackinnoni. The variation in foliar micromorphological characters between the genera and within the species was useful in identification and classification and have potential taxonomic significance for species differentiation. An identification key using micromorphological characters are provided to distinguish genera and species.

Foliar epidermal micromorphology and its taxonomic implications in some selected species of Athyriaceae

Foliar epidermal characters of ten species from the genus Cassia L. Emend. Gaertner, Senna Miller and Chamaecrista Moench found in South Western Nigeria were studied. The aim was to establish some useful diagnostic features that may be employed in combination with other characters as intra or inter-specific or generic tools for their delimitation. Our results revealed exciting features that are helpful in the identification of each species. These include guard cell area, stomatal index and frequency, presence or absence of trichomes, types of trichomes, as well as their length on epidermal surfaces and wall types. These results, therefore suggest diagnostic features that were found on the epidermal surface that can be employed to justify the separation of the new genera Senna and Chamaecrista from their initial genus Cassia.

A taxonomic study of some species in Cassiinae (Leguminosae) using leaf epidermal characters.

A systematic approach to the investigation of foliar epidermal anatomy of subfamily Caryophylloideae (Caryophyllaceae)

Aldama arenaria (Baker) E.E.Schill. & Panero and Aldama robusta (Gardner) E.E.Schill. & Panero are aromatic plants, morphologically very similar and usually confused on the analysis of exsiccates. The present study aimed to identify the secretory structures present in vegetative organs and to survey for anatomical features with diagnostic value between A. arenaria and A. robusta based on an examination of these organs. Aldama arenaria and A. robusta exhibit hydathodes in the dentate ornamentations of the leaf margins and apices in addition to glandular trichomes, secretory cavities and ducts, all of which vary with respect to type and location in each species. Xylopodia and adventitious roots constitute the underground system. The xylopodium is covered by epidermis or by suberised cells resulting from periclinal divisions of parenchyma cells. The tuberisation process of adventitious roots results mainly from hypertrophy and hyperplasia of medullary cells, especially in A. arenaria. Through anatomical anal...

Anatomy of vegetative organs with an emphasis on the secretory structures of two species of Aldama (Asteraceae–Heliantheae)

A comparative study of the leaf epidermis of twelve species in the Compositae (Asteraceae) family was undertaken in order to document characters that are important in the taxonomy of the family. It was observed that trichomes can be successfully used for the delimitation of genera within the family. Within each species however, there are varied assortment of trichomes with occasional transitions among them. Launaea taraxacifolia was unique in being the only species without any trichome. Stellate trichome type and K-shaped or tetraradiate trichomes were observed in Tridax procumbens only. The genus Vernonia can be delimited from the other genera by the possession of T - shaped trichomes which are absent in the other genera, while amoeboid-shaped trichomes can be found in the genus Chromolaena only. Within the same genus, the species can also be delimited on the basis of possession of unique trichome types, for example in the genera Vernonia and Emilia. Cuticular striations occur in only two species out of the twelve studied, on the abaxial surface of V. amygdalina and on both surfaces of Bidens pilosa. Four stomatal types were recorded for the family, anomocytic, brachyparacytic, anisocytic and diacytic. Stomatal type was observed to delimit not only at generic level, but also at specific or species level. Ageratum conyzoides and Synedrella nodiflora are the only two species with occasional diacytic stomatal types. Results of the statistical correlation analysis for stomatal size and stomatal index at the 0.05 and 0.01 levels revealed high positive correlation for species in the same tribe, as well as for species in different tribes affirming close interrelationship and overlap of the values of stomatal indices and sizes within the family. Foliar anatomical characters that justify the separation of Vernonia amygdalina and Vernonia cinerea into separate tribes are highlighted.

O. A. Jewoola

Papers

Importance of Leaf Epidermal Characters in the Asteraceae Family