This is a variable species, especially with respect to the length of the calyx lobes. In the more northerly part of the distribution (e.g. south Thailand) the lobes are short and inconspicuous as above; in the southern part of the distribution (Malaysia, Sumatra) the lobes are longer.
Additional photos in a slideshow may be seen by clicking one of the links below:
- A collection with the longer calyx lobes characteristic of the southern part of the range
- A flower comparison showing variability in the calyx lobes
