Orchids can be incredibly easy to identify or frustratingly difficult.  For instance, the Flying Duck orchid is easily recognizable.  The name says it all. But for many other orchids, particularly the ubiquitous blue sun orchids, it is necessary to make careful observations.

 

 

 

For sun orchids the most important distinguishing feature will often be the column, details of which are described or illustrated in orchid keys.  For example Bates and Weber, Orchids of South Australia (1990) has an illustrated dichotomous keys showing the different types of columns.

With today’s cameras, it is possible to photograph the column, preferably from front, side and above.  This helps greatly with identification.

The following photographs illustrate the variety of columns.

 

 

And it is not only the blue orchids that can be a problem, in South Australia; there are three pink orchids which are different in size and flowering time, features that are not obvious in a photograph,  so the column is a helpful identification tool.

 

And just what is the column? It is the reproductive organ of the orchid flower and is unique amongst plants because it is the fusion of the male (stamens) and female (pistil) parts.  It is usually found in the centre of the flower and both releases and receives the pollen sac.