Sunday, January 06, 2008

Hydnophytum - Part 1 (formicarum)

I wonder if anyone has heard of antplants? Okay, there will always be ants around plants looking out for food - coaxing sugary secretions from mealies, feeding on nectar rich flowers, collecting sweet secretion from nectary glands on leaves giving some protection to Impatiens. More specifically, i shall refer to antplants as plants that provide a home for the ants. The family Rubiaceae has a few highly evolved genus - Hydnophytum, Myrmecodia, Myrmephytum Anthorrhiza, Squamellaria which provide a complex honeycomb structure for housing ants! These plants have a fat stem base or "caudex" that can house ants, and in nature antplants are invariably populated with ant colony. In cultivation, these plants also develop a caudex irrespective of whether ants choose to migrate or live there. There is a symbiotic relationship between plant and ants. Ants provide nutrients and at the same time protect antplants from its insects or even human enemies. While the antplant provides a shelter for ant colony. Well, i don't want to go into the details but Nick Plummer has a good website that covers this topic with a reference list.

Hydnophytum is the genus with the widest distribution from Fuji Islands in the Pacific to Andaman Islands in the Indian ocean and from Southern Indochina to Cape York in Australia.
Let's start off with the better known Hydnophytum formicarum (photo above). This plant is in cultivation in both private and botanical collections for sometime. Various distinctive forms or varieties are available from specialist nurseries time to time and they are mostly labelled as H. formicarum. Personally, these are probably variations of one species complex or have evolved into different species from west to east. Base on regional flora, Hydnophytum represented by one species which is H. formicarum in Andaman Islands, Peninsular Thailand & Malaysia, Sumatra. Observations of wild H. formicarum plants in Peninsular Malaysia and its offshore islets in the South China seas yield little variation. Thai plants are also similar. The leaves are leathery and have prominent veins, tubers are invariably dark brown with ant entrance holes irregularly placed. The "spination" or "bristles " covering the tubers are root stubs which stop growing. Tuber ridges and lobings are irregular. Having seen many seedlings from the same mother plant, the caudex is shaped more by environment conditions then genetics. More to come... in Part 2.

1 comment:

Julie said...

I have been wanting something with a nice caudex, and one of these would be perfect!