Orbicule
Encyclopedia
Orbicules are small a-cellular structures of sporopollenin
(known size range from < 1 µm to 15 µm, but usually sub-micrometre) that might occur on the inner tangential and radial walls of tapetal cells
. Their function is unclear at this moment. Current consensus is that they are just a by-product of pollen wall sporopollenin synthesis.
Sporopollenin
thumb|right|270px|[[Scanning electron microscope|SEM]] image of pollen grainsSporopollenin is a major component of the tough outer walls of spores and pollen grains. It is chemically very stable and is usually well preserved in soils and sediments...
(known size range from < 1 µm to 15 µm, but usually sub-micrometre) that might occur on the inner tangential and radial walls of tapetal cells
Tapetum (botany)
The tapetum is a layer of cells that is found within the pollen sac, a nutritive tissue within the sporangium, particularly within the anther. Tapetum is important for the development of pollen grains. The cells are usually bigger and normally have 2 nuclei per cell...
. Their function is unclear at this moment. Current consensus is that they are just a by-product of pollen wall sporopollenin synthesis.
External links
- A photo of NelumboNelumboNelumbo is a genus of aquatic plants with large, showy flowers resembling water lilies, commonly known as lotus. The generic name is derived from the Sinhalese word Nelum. There are only two known living species in the genus. The sacred lotus is native to Asia, and is the better known of the two...
orbicules: