Septemeranthus: New genus of parasitic flowering plant

In News 

• Recently, A new genus of a parasitic flowering plant(Septemeranthus ) has been discovered from the Nicobar group of islands. 

Image Courtesy: TH

About 

• The genus, Septemeranthus, grows on the plant species Horsfieldia glabra(Blume) Warb. 
  • The parasitic flowering plants have a modified root structure spread on the stem of the tree and are anchored inside the bark of the host tree.
• The name Septemeranthusis derived from the Latin word ‘Septem’ meaning ‘seven’, referring to the arrangement of flowers.
• The genus belongs to the family Loranthaceae, a hemiparasite under the sandalwood order Santalales and is of widespread importance. 
  • Loranthaceae is currently represented by nine genera and are found all across the country.

• Description 
  • The genus Septemeranthus has a 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’ (earthen pot-shaped). 
  • The flowers have five persistent bracts having conspicuous margins. 
• Nutrition:
  • Plants which are hemiparasites are partially dependent on their host plants for nutrition.
    • For instance, the newly discovered plant that derives nutrients from its hosts has green leaves capable of photosynthesis. 

• Role: They play an important role as they provide food for frugivorous birds.
• Distribution: The plant was found on the periphery of the tropical forest in one of the biodiversity hotspots referred to as the Nicobar group of islands separated from the Andaman group of Islands by a wide gap of 160 km with heavy tidal flows.
  • It is endemic only to the Nicobar group of islands. 
• Other related discoveries 
  • In addition to Septemeranthus, four other genera on non-parasitic plants,
    • Nicobariodendron(Hippocrateaceae)
    • Pseudodiplospora (Rubiaceae)
    • Pubistylis(Rubiaceae)
    •  Sphyranthera, (Euphorbiaceae) have also been discovered earlier from the Nicobar group of islands, highlighting the ecological significance of the region. 
  • Recently a new species in the hemiparasitic family Loranthaceae, Dendrophthoe laljiihave also been discovered from the Nicobar group of islands.

Source: TH