---------- Forwarded message ----------
From: Pankaj Kumar <sahanipan...@gmail.com>
Date: Oct 8 2009, 10:32 pm
Subject: Geodorum densiflorum – NSD 38
To: efloraofindia
Dear Sir,
I have made few observations during my 6 years of study some of which
I am discussing below.
Geodorums are very peculiar. A small shoot like green structure
originates from the previous years underground corm that are present
at the end of the chain of corms. Then at a certain point, the shoot
bifurcates, one tip growing into foliar part and the other part
growing into the floral axis, on the onset of monsoon (but both
emerges from the same shoot, so at the lower end if u dig out the corm
you will wild them covered with same foliar bracts). Sometimes, when
the rain abruptly stops the foliar part gets stunted for the time
being, sometimes they even die, but the floral axis gets nourishment
from the previous years corm so it keeps growing. Thats a kind of
successful flowering strategy in this particular orchid. So its not a
big deal if the plant will bear leaves or not during the flowering
period.
Orchids have very peculiar growth habits. Some orchids flower in the
stress when there is scarcity of food material whereas some flowers
when the food material is abundant. Some orchids give both foliar and
floral shoot whereas some gives floral first, whereas some give foliar
first.......In orchids like some species of Eulophias
(Eulophiaexplanata) floral stalk emerges in extreme stress, its like
when the
perrenating underground corms think that they can't bear it anymore
(in the extreme heat of summer at a temperature of around 40 degree
celsius) then they give out small callus like structure near the
previous year's corm. The callus has usually two apices. If the stress
persists then one apice give rise to floral stalk, where as other
remains stunted and when it starts raining, then it becomes active to
give foliar stalk....but if it rains abruptly, then it give foliar
stalk and the plant doesnt flower in that year at all.......
U can see a healthy flower ofEulophiaexplanatagrowing in the
extreme heat of summer, without any leaf, when most of the other herbs
seems to be dying off !!!
..INTERESTING NA !!! :)
Regards
Pankaj