Bifurcation and Ridgeforms
Female Orchid Classification System
Principle of Bifurcation
The word bifurcation literally means to divide into two parts. For a FOCS definition, it applies to the sheath dividing into one, two (or more) parts.
The analogy is to a single main stream (the classical form of the sheath) when that main stream splits into one, two or more tributaries. The FOCS terms bifurcation or bifurcated are used to designate these types of highly recognizable forms of orchids. In bifurcations, the tributaries are really just ridgeforms of the sheath, to the point that, in some orchids, the sheath can’t really be designated as sheath because of such a radical change in form.
The following schematics illustrate the principle.
Bifurcated orchids are illustrated below. In the first example, an unaltered orchid is shown on the left and the illustrated orchid on the right. A prevalent feature of many bifurcations is a distinct bifurcation line splitting the sheath. The key distinguishing factor of bifurcation is that one or more of the tributaries (ridgeforms) may transition/transform/fuse with the labium or labia. Generally, when the orchid is in the natural state, the hood may not visible.
Below are more examples of the most prevalent types of bifurcations.
There too numerous bifurcation variants to illustrate them all, however, below are more examples to demonstrate some of the range of variants. The important point is that all conform to the basic principle of tributaries splitting the sheath.
Most of the previous examples illustrate two stream bifurcations. Again, highlighting the number of variations, below are more complex varieties of asymmetric (not mirror image) bifurcated orchids.
