Neil Bromhall
July 13th, 2010, 10:12 AM
I've added a time-lapse of a Digitalis flower.
http://www.youtube.com/user/neilbromhall#p/a/u/0/SNjH8u6TxJ8
The flowers are interesting.
The pollen sacs split before the stigma opens.
This is to lessen the chance of the flower being self pollinated.
Bumble bees usually start at the bottom of the Digitalis flower spike. The lower flowers have the sticky stigma extended which collects pollen transported on the back of a bumble bee which it brought over from the previous flower.
As the bumble bee climbs up the flower spike it collects pollen on it's back yet the stigma of the higher flowers on the spike are closed so as not to be self pollinated.
I hope this time-lapse helps show how fascinating this flowers is.
At the end of the sequence you can see the pollen sacs opening and then later the stigmas extends and splits. The quality of the image is not brilliant on Youtube but I hope it gives you an idea.
http://www.youtube.com/user/neilbromhall#p/a/u/0/SNjH8u6TxJ8
The flowers are interesting.
The pollen sacs split before the stigma opens.
This is to lessen the chance of the flower being self pollinated.
Bumble bees usually start at the bottom of the Digitalis flower spike. The lower flowers have the sticky stigma extended which collects pollen transported on the back of a bumble bee which it brought over from the previous flower.
As the bumble bee climbs up the flower spike it collects pollen on it's back yet the stigma of the higher flowers on the spike are closed so as not to be self pollinated.
I hope this time-lapse helps show how fascinating this flowers is.
At the end of the sequence you can see the pollen sacs opening and then later the stigmas extends and splits. The quality of the image is not brilliant on Youtube but I hope it gives you an idea.