Septemeranthus is partially dependent on its host but also has leaves capable of photosynthesis
A new genus of parasitic flowering plant has recently been discovered in the Nicobar group of islands. Genreseptemeranthusgrows on plant species Hairless Horsfieldia(Blume) Warb. Parasitic flowering plants have an altered root structure distributed over the stem of the tree and anchored inside the bark of the host tree.
The plant was found on the outskirts of the rainforest in one of the biodiversity hotspots called the Nicobar group of islands separated from the Andaman group of islands by a 160 km wide gulf with strong tidal currents.
heart shaped leaves
Genreseptemeranthushas distinct vegetative morphology, inflorescence architecture and floral characters. The leaves of the plant are heart-shaped with a very long tip and the ovary, fruit and seeds are ‘urceolate’ (shaped like an earthen pot). The flowers have five persistent bracts with conspicuous margins. The name septemeranthusis derived from the Latin word ‘septem’ meaning ‘seven’, referring to the arrangement of flowers. Details of the find were published in theJournal of Botanical Taxonomy and Geobotany Feddes Repertorium.The genus belongs to the family Loranthaceae, a hemi-parasitic of the order Santalales of sandalwood and is of great importance. Plants that are hemiparasites depend in part on their host plants for their nutrition. For example, the newly discovered plant that derives nutrients from its hosts has green leaves capable of photosynthesis. The Loranthaceae are currently represented by nine genera and are found throughout the country. .What makes the new genus unique is that it is only endemic to the Nicobar group of islands. Lal Ji Singh, co-director of the Botanical Survey of India, which discovered the genus, said: “During field studies, I found that birds consume slimy seeds of this new genus and that seeds have a pseudo viviparous germination potential which settle on the leaves and branches of their same plant which is already attached to host plants. After germination, the life cycle of the genus begins again.
Hemi-parasites are commonly referred to as mistletoe which contain 18 families, 160 genera and over 2,200 species. They need a host tree or shrub to thrive and have a worldwide distribution in tropical and temperate habitats which have evolved about five times. in order and are important in forest ecology, pathology and medicine. They play an important role as they provide food for fruit-eating birds. In addition to Septemeranthus, four other genera on non-parasitic plants, Nicobariodendron(Hippocrataceae),Pseudodiplospora (Rubiaceae),pubistylis(Rubiaceae),Sphyranthera, (Euphorbiaceae) were also discovered earlier in the Nicobar group of islands, highlighting the ecological importance of the region. Recently a new species of the hemiparasite family Loranthaceae,Dendrophthoea laljiihave also been discovered in the Nicobar group of islands.