A type of thistledown. The fact that plant species here choose wind dispersal of their seeds does not surprise one, for the shore - to state the obvious - is a windy place. Tucked within that fluffy white downy material, composed of many fine and frail strands, is a seed - the achene - with the surrounding sphere of frail, fluffy, white strands being called the pappus, at least in the disk achenes.
The dandelion too has a similar structure with the difference that the downy fluff does not extend all around the seed in the dandelion but occupies only a parachute-like portion above the suspended seed. It does not matter, the operating principle is the same in both cases - namely that the the high surface area of that conglomerate of loose fine strands helps the seed not only to catch the wind, but, more importantly, to be lofted up and away, almost as if it were winged.
The plant obviously wishes to disperse its seed to the greatest possible distances, and the parameters that determine this are wind velocity and the height of release from the parent plant.
This of course is expected. What is not expected is that the HUMIDITY of the atmosphere also determines the distance of travel. In a fascinating paper by McEvoy & Cox, published in 1987, it is stated that a high humidity decreases the distance of travel for it cause the fine strands of the pappus to become matted, the surface tension of water literally stitching them together, making them lose their lifting power, much as our fluffy hair becomes a matted mess after a shower.
This matters here, on Machilipatnam Beach, for as will be shown in a subsequent photo, the air here is so thick with humidity, that it almost seems to hang like a suspended mist over the shore, clearly compromising the distance of spread of the seed.
There is no hope for this particular achene however. Having come in contact with the wet surface of the shore, it is never ever going to get off again..It is doomed, and one is dismayed, for it it is so light and lovely, delicate and beautiful, that one would have wished it to succeed in its quest for life.
Machilipatnam Beach. July 19, 2019. Andhra Pradesh.
