Anatomy of rachis, petiole and petiolule in 43 species and 20 genera of Euphorbiaceae are investigated. The mechanical tissues in these organs are invariably sclerenchymatous and collenchymatous. The xylem elements are additionally mechanical in function. The occurrence of vascular tissues is in the form of distinct bundles, only an arc-shaped strand or a continuous cylinder. The cortical bundles are noted in Aporosa and Jatropha gossypiifolia while unequal sized central vascular bundles are observed in Mallotus nudiflorus and M. philippensis. The variation in the distribution of sclerenchyma, collenchyma and vascular patterns apart from the shapes as observed in a transverse section of the leaf stalk can be used for the delineation of the taxa studied.

Taxonomic significance of the rachis, petiole and petiolule anatomy in some euphorbiaceae

Nodal anatomy reveals the number, behavior and fait of bundles in each node and internode. Firstly, three main types of nodes represented by the one trace- one gap, the three trace- three-gaps, and the multi-traces- multi gaps in plants were proposed. Then the fourth types of nodes, represented by two- multi traces - one gap , was added to nodal types, while the fifth type (split –lateral) has been proposed, where a single trace associated with numerous leaves by splitting as found in different families from Angiosperms.Branches traces are distinct from leaf ones, and it represented of one or several bundles formed in axillary of leaves, commonly branch trace and middle leaf trace formed with the same gab,One of the important facts of studying nodal anatomy is the relationship between nodal structure and leaf base referring to stipules and sheathing base as well as the phyllotaxy. In monocot plants leaves characterized by sheathing bases, So the leaves nodes appeared with numerous leaf traces separated from different stem bundles, in Dicots plant different nodal types recognized.the studies of nodal anatomy are considered as an important features in taxonomical studies and phylogenetic studies on Dicots plant, most the studies revealed the di-traces and tri-traces nodes considered as primitive type while the uni-trace or multi-traces node are the advanced and it was proposed either by reduction or amplification.

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A review in nodal anatomy for plants

Anatomy of the petiole of Vitex negundo is investigated. It is naturally distributed in many parts of Maharashtra and Marathwada. In this study the aim was to investigate the anatomical characters of rachis and petiole of this economical important plant species. As a result of study, it was discovered that the mechanical tissue in the form collenchyma or sclerenchyma occurs in petiole and Petiolule. The xylem elements are additionally mechanical in function. The vascular tissue in the form of distinct bundles or an arc shaped strand is observed.

A Study on Petiole and Petiolule anatomy of Vitex negundo. L (Verbenaceae)

Anatomy of the rachis, petiole and petiolule in 15 species distributed over 13 genera of Meliaceae is investigated. The mechanical tissues in these organs are invariably sclerenchymatous and rarely collenchymatous. Vascular tissue in the form of distinct bundles, an arc-shaped strand or a continuous cylinder is noted in different organs. Medullary bundles occur in Walsura and Aglaia, while cortical bundles are present in Aphanamixis and Khaya. Both the types are seen in Soymida. A key based on the anatomical characters of the leaf stalk is provided for the delineation of the taxa studied.

N. P. Vaikos

Papers

Taxonomic significance of the structure of the rachis, petiole and petiolule in Meliaceae