Question

Give the list of gymnospermic plants distributed in north east india

Answer 1

The name gymnosperm derived from the Greek word, ‘gymnospermos’ (‘gymnos’ – naked, ‘sperma’ – seed) meaning naked seeds; ovules are naked and freely exposed to pollination, and the fertilized seeds are not enclosed by carpels. The ovules are embedded in a leaf–like structure (homologous to a leaf), or on a scale or megasporophyll (homologous to a shoot) or on the apex of a (dwarf) shoot. Gymnosperms are also characterised by various other characters such as absence of companion cells, presence of orthotropous, unitegmic three-layered ovules, anemophilous pollination, absence of double fertilization, formation of endosperm before fertilization, presence of polyembryony and manoxylic wood.

Gymnosperms are currently placed in five distinct and widely divergent orders namely Cycadales, Ginkgoales, Taxales, Coniferales and Gnetales. Hooker (1888) reported 42 taxa (40 species and 2 varieties) belonging to 16 genera under three orders namely Gnetaceae, Coniferae (with 6 tribes viz. Cupressineae, Taxidieae, Taxeae, Podocarpeae, Araucarieae and Abietineae) and Cycadaceae from then British India, of which only 33 species and 2 varieties were from the present political boundaries of India.

According to Maarten & al. (2011) there are 1026 species in 84 genera in the world in almost all continents, except Antartica. Singh & Srivastava (2013) reported 146 species and 8 varieties (indigenous/introduced) of gymnosperms in 46 genera belonging to 12 families from India.

In addition to their ornamental value, the Gymnosperms are of much use to the human beings as they provide valuable timbers, wood pulp, soft wood, resins, edibles and medicines

Answer 2

Plant diversity in Northeast India comprises elements ... range of distribution and conservation status is given and threats .... The plant list will clarify the present.