{{Short description|Reproductive structure that can be found in several plant families}} {{One source|date=February 2024}} [[Image:StylidiumFlora5.jpg|thumb|200px|right|Flower of ''Stylidium turbinatum'', showing the column.]] The '''column''', or technically the '''gynostemium''', is a reproductive structure that can be found in several plant families: Aristolochiaceae, Orchidaceae, and Stylidiaceae.
It is derived from the fusion of both male and female parts (stamens and pistil) into a single organ.<ref>{{Cite web |url=http://www.botany.hawaii.edu/faculty/carr/orchid.htm |title=Flowering Plant Families |last=Carr |first=Gerald |date=30 October 2005 |website=Vascular Plant Family |publisher=University of Hawaii Botany Department |access-date=3 August 2022}}</ref> The top part of the column is formed by the anther, which is covered by an '''anther cap'''. This means that the ''style'' and ''stigma'' of the pistil, with the filaments and one or more anthers, are all united.
== Orchidaceae == thumb|right|400px|{{center|Longitudinal view of a vanilla flower, showing the column }} The stigma sits at the apex of the column in the front but is pointing downwards after '''resupination''' (the rotation by 180 degrees before unfolding of the flower).{{cn|date=February 2023}}
This stigma has the form of a small bowl, the '''clinandrium''', a viscous surface embedding the (generally) single anther. On top of it all is the '''anther cap'''. Sometimes there is a small extension or little beak to the median stigma lobe, called '''rostellum'''.{{cn|date=February 2023}}
'''Column wings''' may project laterally from the stigma. The '''column foot''' is formed by the attachment of the lip to the basal protruding part of the column. One speaks of a '''mentum''' (chin) if the lateral sepals are also basally adnate (which are attached to the foot of the column).
The column both releases pollen and also receives it (from another individual) for fertilization. In the family Orchidaceae, unlike almost all other flowering plants, the single male anther at the tip of the ''column'' produces pollen that is not free and powdery but held in waxy masses of two, four or six pellets called '''''pollinia'''''. The transfer of ''pollinia'' from one flower to another, though highly efficient, is often reliant upon one particular species of arthropods and it can be catastrophic for the population if its pollinator disappears from the community.
== References == {{Reflist}}
{{botany}}
Category:Plant morphology Category:Pollination Category:Orchid morphology