Upon removal of whole pollinarium by a pollinator the pollinia may change their angle of orientation as the caudicles and/or stipes dry out and change positions (see also, Darwin, 1877).
Floral architecture and floral dimensions limited the number of visiting animals that functioned as legitimate pollinators as the pollinium or pollinarium was fixed specifically to the part of the vector's body that contacted the receptive stigma when it visited a second flower on a second plant of the same species.
Pollination and pollinarium of Dipodium punctatum (Sm.
1999, "Temporal variation in pollinarium
size after its removal in species of Bulbophyllum: a different mechanism preventing selfpollination in Orchidaceae", Plant.
The 1-millimeter-long fragment of a pollen-bearing structure, or pollinarium, rests on the back of a stingless bee that became trapped in amber about 15 million to 20 million years ago.
Because the pollinarium fragment appears to be stuck in the middle of the bee's back, the researchers speculate that the insect had to crawl into the orchid's flower to pollinate it.
Characteristics of the pollinarium fragment place the ancient orchid in the subgroup Goodyerinae.
As in the Asclepiadoideae, the pollinarium consists of a corpuscle and pollinia.
In these cases, each pollinarium contains only two functionally efficient pollinia , which is reminiscent of the situation in the Asclepiadoideae.