Ants & Plants, Ant Plants
Ants and plants do have a love-hate relationship that went with their evolution. Some ants destroy plants by chewing them, cutting them, toppling them, raising mealy bugs, aphids, and scales that suck the plants’ juices rendering them frail and weak. Some ants nurture their host plants by providing them with their self-made fertilizers, cleaning them, defending them ferociously against potential predators, killing other plants that might just happen to rest or coil beside their hosts. And we are just beginning to understand the complexities of this love-hate relationship.
This blog will deal with the love relationship issue rather than the other kind of relationship.
Several genera do have one or two species that have evolved to act as ant hosts. For the genus Hoya, H. imbricata and H. darwinii are representative ant plant species here in the Philippines. The former is indigenous and has leaves that have their own individual roots on the underside that attaches itself to tree trunks and other media. Ants may thrive under the leaves and completely be safe from the elements and predators. H. darwinii develops two kinds of leaves, the regular leaves and the dichotomous spherical leaves that could be used as shelter by the ants.
The closely related genus Dischidia has D. purpurea, D. platyphylla, D. vidalii, D. cleistantha, and D. major as representative species from the Philippines. I hope my own Dischidia is a new undescribed species. This genus has not undergone extensive examination and study compared to its sister genus Hoya and many more species await discovery. D. purpurea and D, vidalii resemble each other very closely and might in the future be just lumped together upon further study. Both have two leaf forms: the regular ones and the imbricate leaves that might serve as ant homes. D. platyphylla has somewhat golden yellow semi-imbricate leaves which growth habit is akin to H. imbricata, the leaf edges are curly. Most ant plant Dischidias have two leaf forms. They have small, often insignificant flowers. Their interesting feature is the imbricate leaves.
In the Bromeliaceae, Tillandsia butzii have leaf bracts that serve as ant homes. This is my most favourite Tillandsia species because of the scripture-like markings on the leaf bracts. They are sluggish growers and Ate Aireen Bernal, my sparring “plant” partner advised me to grow this plant hanging upside down so as to keep the bracts from being water logged that contributes to its quick demise.
Several Acacias in the Fabaceae family host ferocious stinging ant species. The large, inflated thorns of the whistling-thorn acacia (Acacia drepanolobium), an African swollen-thorn acacia species, are in the wild, occupied by symbiotic stinging ants of the genus Crematogaster that protect the tree from destructive herbivores. The bulbous thorns are not galls and will develop with or without their symbiotic ant partners.
Platycerium madagascariensis and Platycerium ridleyi are ant ferns. In the Philippines, Lecanopteris is the genus of ant ferns. The fleshy part of the plant that adheres to a medium serves as the home of its ants and makes the plant bottom heavy due to its weight. It is also from these fleshy parts where the leaves arise. Solanopteris is the new world equivalent of the genus Lecanopteris.
Then there are the genera that are true ant plant specialists: Myrmecodia and Hydnophytum of the Hydnophytinae subtribe in the Rubiaceae (coffee) family, and the lesser known genera of Anthorrhiza, Myrmephytum, and Squamellaria are also members of the same subtribe in the same coffee family. The base of their stems develop into large tubers. Tissues die back within the tubers and these gives rise to the myriad galleries that are accessed through the numerous holes seen on the caudices’ surface. These galleries act as chambers for the various needs of the ants. In Myrmecodia, galleries come in two forms: ant habitats that are dry smooth-walled and garbage area that is warty. The garbage of the ants are rich fertilizers for the plants. Hydnophytums are less lavish than Myrmecodias with the warts mostly found at the end of the galleries. Clypeoli, shield-like structures, surrounding the base of the leaves are usually seen covering the stem of the genus’ species; however, there are exceptional species that poorly or really does not have clypeoli at all. At the alveoli, hollow-like structures, flowers develop. Hydnophytums have thinner multi-branched stems that possesses no alveoli nor clypeoli; they are distributed from South Africa to Australia, Fiji, and the Philippines. The former genus is more restricted in distribution with New Guinea as its centre of diversity.
Mymecodia, Hydnophytum, and Lecanopteris are often seen in specialized individual collections but most of these are not quite growing well. These are epiphytic plants that are found attached to high portions of trees in their native habitats where there is abundant sunshine, air movement, and the security of being not water-logged.
If you want to try raising ant plants, go for Dischidias as they are the easiest to cultivate and grow from cuttings albeit a large specimen is a sight to behold. Hoyas and true ant plant genera require more specialized cultivation.
Tillandsia butzii is now more commonly sold (albeit I know of only one store selling hundreds if not thousands of this species) and so the price is cheaper compared to other ant plants.
My ant plants have shiny smaller-than-usual black ants that seldom show out of their homes except when you rattle them or pour copious amounts of water on the plants’ caudices. While ant plants can live even without their ants, I am of the belief that they are better when they have them.
I have tried my hands with most of the plants I discussed here and the lesson I learned in taking good care of them is vigilant observation and monitored watering specially if they have resident ants on them.
My very first encounter with an ant plant was when The Philippine Orchid Society held its February show at the Rustan's Shangi-La Mall in Mandaluyong City. I found the small stemmed, fat caudex so enigmatic and unique that I bought and tried to raise it myself. It would have fared well however, since I placed it in my Binangonan garden and I'm always in Mandaluyong City being then a tertiary student, the plant died of neglect yet I didn't-nor will ever give up on these Philippine endemic succulents!
Next, I bought an ant plant-a Hydnophytum this time, to be displayed at the Cactus and Succulent Society of the Philippines, Inc. booth during the 2009 Horticultural Society of the Phliippines, Inc. annual garden show and exhibit. I do not have the leisure of time transporting my succulents from Binangonan to Manila Seedlings Bank Foundation in Quezon City where the show was held due to my busy school schedule so I just bought some plants instead including that ant plant. It even do have fruits! But it also did not last long due to the same reason.
After that, i went on an expedition with a seasoned plant hobbyist cum native trees landscaper and another plant hobbyist around the Rizal-Laguna-Quezon provinces looking for plant/garden stores and found my quarry and a what a fine specimen I acquired-a matured, robust Myrmecodia tuberosa and there were ants inhabiting it! This time I tried planting it in soil with the tuber somewhat raised and watered it lavishly but still i failed. This time because the plant was waterlogged.
Around two years passed again and I learned of a weekend market that has plant vendors and when I got there, luckily I found they were selling ant plants! A small Myrmecodia but with a caudex that makes up around 70-80% of the plant's entirety. This time it was without any medium and seldom watered. I tried raising it here in my Mandaluyong Garden but the problem this time is that there's too much heat since the G.I. sheet roofing is low and it wasn't yet a proper garden then.
Oh heavens! This plant is really posing horticultural problems! Yet I will never, ever give up on them until I find the right formula to successfully raise them and this time I'm trying again and learning more about them.
