Comparative chemotaxonomic investigations on amaranthus hybridus l. and <I>Amaranthus spinosus L.</I>

Abstract

The present study is set to investigate the comparative chemotaxonomic investigations on Amaranthus hybridus L. and Amaranthus spinosus L. which belong to the family Amaranthaceae. They are dicots pre-dominantly found in the Niger Delta Tropics, Nigeria. The species are annual erect herbs with flower inflorescences as elongated spikes which are mostly paniculate occurring at ends of branches in globose fashion in axils of leaves.The nodes often have pair of axillary spines. Flowers are small, greenish with male ones at the top while the female ones below the clusters and stem is greenish but often reddish with one-seeded capsule as fruit in Amaranthus spinosus which attains up to 80 ± 20cm in height whereas A. hybridus differ in absence of a pair of axillary spines, the stems are greenish or slightly pinkish which grows up to 100 ± 10cm in height. A. hybridus is more of a vegetable and has alternate phyllotaxi and narrow cuneate base. Fruits from both species are circumscissile capsules and their inflorescences are terminal racemes positioned at their axils with female perianth segments of five. Epidermal studies revealed amphistomatic stomata which is anisocytic  type for both species. The stomatal index for A. spinosus adaxial foliar epidermis is 20% and the abaxial 20% whereas for A. hybridus adaxial is 20% and abaxial foliar stomatal index of 20%. Anatomical studies revealed open vascular system, collenchyma dominating the hypodermis while parenchyma occupied the general cortex and pith regions. A. hybridus has more vascular bundles and trichomes, and wider pith than A. spinosus. Phytochemical studies showed the presence of tannins, saponins, alkaloids, and flavonoids are present in A. spinosus while alkaloids were absent only in A. hybridus. This may be the reason why A. spinosus is used more in tradomedicine than A.hybridus which served more as vegetable.