This ant plant, Hydnophytum moseleyanum Beccari, is an epiphyte native to lowlands from Queensland, Australia to Papua New Guinea.

Hydnophytum moseleyanum [hid nof' e tum mo sel' ee an um] has a caudex, a swollen base of the trunk. The caudex begins developing shortly after the seed germinates—the hypocotyle, the area of the stem between the soil line and the seed leaves, bulges even before any true leaves develop.

As the caudex develops with the growing plant, domatia (chambers) form by the death of groups of cells. Domatia connect into a series of rooms; several have openings to the outside which encourage ants to move in. The chambers in Hydnophytum have smooth walls except at one end where bumps cover the walls. According to Nicholas Plummer (2000), these bumpy areas are where ants dump their garbage—ant feces and remainders of bugs. The bumpy tissues absorb nutrients from the waste.

When I purchased my first Hydnophytum at Selby Botanical Garden, I asked about the odds of having ants move in. To the best knowledge of the horticulturalist, "No, none would move in. We simply did not have the correct species of ants present in Florida."

HA!

Several years ago, I brought that ant plant indoors when a fast moving cold front threatened. The plant was placed in the bathtub for the night. In the middle of the night, the bathroom was filled with ants—tiny ghost ants, small black ants, and large harvester ants. Thinking I would have to spray the room with insecticide in the morning, I shut the door and hoped I'd trapped most of the ants.

But in the morning, there was not a single ant to be found. Obviously, all had returned to their homes inside the plant. The following evening, also a cold night, I watched the plant. The small black ants had a home under the caudex. But the ghost and harvester ants shared the domatia. Surprisingly, the ants did not appear to hold any hostilities toward each other.

I noticed over the years of growing that first ant plant that I never found a single mealybug, aphid, or scale on the plant. And the plants sitting adjacent on the bench had few insects attack them.

(Compiled from: The Ants, Bert Hölldobler and Edward O. Wilson, Belknap Press of Harvard University Press, Massachusetts, 1990; Cultivation of the epiphytic ant-plants Hydnophytum and Myrmecodia, Nicholas Plummer, Cactus and Succulent Journal, 72, 2000; personal communication with a horticulturalist, Selby Botanical Garden, Sarasota, FL, 1992; personal observations of the genus)