Many well-diverged hybrids of P. armeniacum, P. micranthum
and P. delenatii currently exist in the slipper orchid market worldwide.
These hybrids are morphologically similar in some cases
(Fig. 1), particularly in vegetative parts, and are very difficult to identify accurately. The rDNA-ITS region have been used in phylogenetic
analysis in plants at generic and intrageneric levels. The
length and sequences of ITS regions of ribosomal RNA gene repeats
are believed to be fast evolving and therefore may vary. Universal
PCR primers designed from highly conserved regions flanking
the ITS, relatively small size of the ITS region and high copy num-