Caudexed Epiphytic Ant Plants - Part I

[XYZ]

Recently, a friend asked me to provide some background information and photos of my caudexed ant plants (Rubiaceae/Hydnophytinae) for a short article that was published in the San Francisco Chronicle to promote the Pacific Orchid and Garden Expo at the end of February. I presume that many palm growers that read this forum and who don’t reside in SE Asia or NE Australia will be unfamiliar with this amazing group of plants, many of which have elaborate symbiotic relationships with ants, other arthropods, small vertebrates and even other plant families.

This subfamily of largely epiphytic caudexed myrmecophytes is slowly beginning to develop a larger horticultural following as an increasing number of genera and species are becoming available to growers of tropical exotics in the west. Perhaps unsurprisingly, carnivorous plant and species orchid growers, rather than cactus and stem succulent specialists, appear to be the market driving this new interest. Until quite recently there were only a handful of somewhat unremarkable species available representing the two best known genera (Hydnophytum and Myrmecodia), and then only from a very few commercial sources in the US and the EU. Thanks to recent efforts made by roughly a half dozen German, SE Asian and US botanists, collectors and nurserymen, all five genera are now in cultivation for the first time ever, with four of them now available commercially.

Great plants for adventurous tropical epiphyte growers who gravitate to the “wild side”. They are generally not difficult to grow but are mostly intolerant to prolonged spells below 10 degrees C/50 F.

As an aside, there are also quite a few palms that are commonly associated with ants, including a widely-distributed rattan, Korthalsia robusta, as well as many of the clustering, swamp-dwelling Bactris spp. that often harbor colonies of very aggressive ants as backup secondary defenses to their formidable spines.

This group remains surprisingly underrepresented in US public gardens, with the Matthaei (U of Michigan), Huntington, Marie Selby and Atlanta BGs having the best off-exhibit collections. The two finest collections in the EU are private (also true here in the ‘States), although Nancy and Leiden BGs also have noteworthy hydnophytine diversity in their collections.

I currently grow 54 species, subspecies and ecotypes of four genera here in the US; Myrmecodia, Myrmephytum, Hydnophytum and Squamellaria. Most species are warm/hot to intermediate growers, although some of the most striking montane species from Indonesian Papua require constant high humidity and cool nights to survive in cultivation long-term.

New Guinea is the center of species diversity for hydnophytines. All five genera occur there, with one (Anthorrhiza) being endemic to the eastern coastal regions of Papua New Guinea. They occur from mangroves at sea level up to elfin forest over 3,500 m/11,400’). During the past five years, there have been a couple of amazing finds in remote parts of the island. Until 2013, almost none of the more spectacular species native to New Guinea or the islands nearby were in cultivation. This has changed abruptly and very recently as relatively tiny amounts of very delicate and short-lived seed has found its way into specialist collectors’ hands from remote origins and has been grown on successfully…so far!

There is a superb website originally set up by the well-respected German botanical explorer and nurseryman, Dr. Andreas Wistuba, now curated by US myrmecophyte specialist Frank Omilian, that has a huge amount of information on growing ant plants of all families. The website also showcases some amazing photographs taken in situ by Dr. Wistuba and New Zealand plantsman, Derrick Rowe, and others. If you are not already familiar with it, I strongly suggest that interested readers check it out at: http://myrmecodia.invisionzone.com/.

I have included a number of images of some examples from my own collection of the incredible and bizarre forms the caudexes of these plants can assume. To show as much variety as is reasonably possible, I have included more images in a separate post (Part II).

Cheerio,

J

 

Hydnophytum puffii - Sarawak, Malaysia

Myrmecodia erinacea - Indonesian Papua

Myrmephytum selebicum - Samar, Philippines

Squamellaria guppyana - Solomons

Cross-sectioned Myrmecodia tuberosa var. papuana from FN Queensland showing natural internal chambers

[Gonzer]

Fantastic plants and great info Stoney, thank you.

[Peter]

Very cool!

[Palmarum]

Very interesting group of plants. I haven't seen any myself in S. Florida, but would be neat to try them.

Ryan