More ant plants

Myrmocophytic plants have evolved independently in many parts of the world - with representatives in the Bromeliad (Pineapple), Euphorbiacea (Spurge), Ferns (Pteridophytes), Rubiacea, Asclepiad (eg Dischidia and Hoya), Orchids and even the pitcher plant family (Nepenthes). The deal is as follows: the plants provide shelter and perhaps food for the ants in return for protection from herbivores - these ants are aggressive ! However, isotopic tracers have found that nitrogenous materials brought by ants are also absorbed by these plants, and to complicate the relationship, some ants are said to spread mealy bugs to the plants.

 

This is the representative of a local tropical ant plant: Hydnophytum formicarum, found at a rather open position.  This plant has small white flowers and bright orange fruits. The hollow tuber is a myriad of ant chambers. In SE Asia and the tropical Pacific islands, Rubiacea is a large family with many interesting representatives of this habit -see also Nick's webpage.

Phymatodes sinuosa is an ant fern found in many lowland localities in SE Asia- the thick hollow stem is often inhabited by ants.

 

The cabbage-like basal fronds of Platyceriums (staghorn ferns) is also a hot bed for ants, not to mention other epiphytes,  tree frogs, snakes and other creepy crawlies. 

Shown here is a P. ridleyii.

Pachycentria is of the Melastoma family, the genus consist of 8 species (according to Gudrun Clausing) of mainly epiphytic plants closely related to Medinilia. It is found in Burma, Thailland, Malaysia, Borneo, PNG, The Philippines, Sumatra, Java and Sulawesi.

Left: Bloom of P. varingiifolia.

Right: The P. constricta has a large tuberous root which becomes hollow upon aging. Ants then inhabit the area. Ants also help to disperse the seeds. In Indonesia, the roots are eaten by women after childbirth.

 

Below: The 2 photos show the plant and closeup of the swollen nodes in the roots of P. glauca ssp maingayii from W. Malaysia.

 

Left and below: A Pachycentria in the wild (photo from West Malaysia). This species has leathery leaves that are red below but no noticeable bulbous roots so it may not be an ant plant.

 

 

 

Left & Right:

The stems of Macaragas (Euphorbia family) have entrance pores from which ants can enter the hollow stems. They also produce food bodies to feed the ants. In the right photo, you can see the pores along the stem which facilitate ants movements. 

In addition to the above,  Dischidia and some Hoyas are also known to be symbiotic with ants. 

Cultivation notes of Rubiacea family : From Cactus and succulent journal