Habitat and Ecology
​Hydnophytum formicarum, commonly known as the Ant Plant or Baboon's Head, is an extraordinary epiphytic caudex subshrub native to Southeast Asia, with a broad distribution from Myanmar and Thailand through the Indonesian Archipelago (Sumatra, Borneo, Java) to New Guinea and even Queensland, Australia. It is a myrmecophyte, meaning it has a mutualistic relationship with ant colonies. It grows on the trunks and branches of trees in various forest types, including lowland evergreen, montane, and mangrove forests, requiring high heat, bright filtered light, and high humidity.
​Description
​This plant is highly prized for its unique, swollen base called a caudex (tuber), which is a massive, woody, above-ground stem storage organ. The caudex is typically irregularly lobed, brown, and deeply tunneled with a complex, naturally formed labyrinth of internal chambers (domatia) that are inhabited by ant colonies in the wild. The caudex can grow up to 15-25 cm across. The slender, simple stems (up to 20 cm long) emerge from the top of the caudex, bearing small, thick, leathery, elliptic leaves that are dark green. It produces small, inconspicuous pale white flowers in the leaf axils, which are followed by decorative, narrowly ellipsoid, orange-red berries. This species is distinguished from its close relative, Myrmecodia, by its smooth, unspiny caudex surface.
​Cultivation
​Hydnophytum formicarum is a warm-growing tropical caudex plant that requires heat and high humidity, best suited for a terrarium, vivarium, or warm greenhouse in the UK. It needs bright, indirect light and can tolerate some filtered sun, but protect the leaves and especially the caudex from intense, direct midday sun. The plant should be potted in a very porous, airy, and fast-draining epiphytic mix (e.g., orchid bark, pumice, and a small amount of coir). The caudex should be primarily exposed above the growing medium to prevent rot. Allow the substrate to dry out almost completely between waterings, but maintain high humidity (60-80%+).
​Optimal Daytime Temperature: 21-30 C (70-86 F)
​Optimal Nighttime Temperature: A small drop is acceptable, ideally 12-18 C (54-64 F).
​Feed very sparingly (monthly, highly diluted liquid feed) during the growing season.
​Unique Features
​This plant is a botanical wonder and a spectacular collector's piece due to its massive, bizarre, chambered caudex, which serves as a natural ant habitat (myrmecodomous). The plant absorbs essential nutrients (nitrogen, carbon) from the debris left by the ants within the internal maze of tunnels. Successfully growing the plant with its striking, swollen base makes it an unparalleled conversation starter and a unique piece of living sculpture.
​Specifications
​Plant Size: as can be seen in the picture
​Plant Family: Rubiaceae
​Plant Passport: A Hydnophytum formicarum B 140084 C [user input] D GB