Origin and Habitat: Australia, New Guinea, Indonesia, and the Philippines. Type: Admiralty Islands.
Habitat and ecology: The epiphytic myrmecophyte Hydnophytum mosleyanum is found in nature growing on trees in the tropical rain forests, also occupying mangrove trees. This plant forms a complex ecological relationships with the Philidris ants. The relationship is mutualistic. The epiphyte gets sustenance by absorbing nutrients from the detritus stored inside tree cavities by the ants, and the ants obtain honeydew secreted by scale insects attracted to the shoot tips of the host mangrove tree.

• Hydnophytum moseleyanum Becc.
• Hydnophytum montanum Scheff.

• Hydnophytum moseleyanum Becc.
• Hydnophytum montanum Scheff.
• Hydnophytum moseleyanum var. teysmannii Becc.
• Hydnophytum papuanum Becc.

Description: Hydnophytum moseleyanumSN|7470]] is an unusual exclusively epiphytic plant that develop a chambered caudex (or broadened stem)at the base of their stems, that provides shelter for ants. The caudex is smooth reasonably large. In nature the ants live in it, and deposit waste which is beneficial to the plant. Technically they are called myrmecophytes which translates as ant-plants. The plant has slightly succulent leaves and makes long, thin stalks which will form a nice and compact whole if pruned. In the axil of the leaves small, subtle flowers can grow, which are followed by yellow-orange berries.
Tuber(caudex):Horizontal to pendent, globose, to 25-38 cm across, the tuber has very complex cavities inside which some arboreal ant species inhabit. The cavities are of two kinds: deep-lying, densely closed-type cavities with warted walls, and superficial, largely smooth-walled open-type cavities.
Stem: Many, succulent, cylindrical, up to 1 m, often much-branched.
Leaves:* Elliptic, or ovate-elliptic to lanceolate-oblong, slightly succulent, 5-8 long, 2.5-5 cm wide, apex acute to obtuse, base attenuate, cuneate to rounded, subsessile or with a short, thick, abruptly attenuate petiole to 2 mm long, lateral vein 3-4 per side of midrib, more or less concolorous, pale green and matt above.
Inflorescences: The inflorescences are produced the axil of the leaves.They very contracted, short and blunt (tuberculiform) with scattered uncoloured indumentum. Flowers are sessile and clustered.
Flowers. Calyx cup-shaped, glabrous, segments very short, entire, truncate, not ciliate. Corolla club shaped 4-5 mm long, white, lobes ovate, apiculate, cucullate (shaped like a hood.). Bottom part of corolla hairy among the base of stamens. Throat ring not hairy. Anthers sagittate (shaped like an arrowhead), filament short fixed above the middle.
Fruits: 7-8 mm, yellow-orange to bright coloured.
Similar species: Hydnophytum moseleyanumSN|7470]]SN|7470]] is a widespread and variable species. Hydnophytum moseleyanumSN|7470]]SN|7470]]s and Hydnophytum moseleyanumSN|7470]]s are often confused.  The easiest way to tell them apart is by the veins in the leaves - formicarums have 6 to 12 pairs of small veins coming off the midrib, moseleyanums only 3 or 4 pairs.

Bibliography: Major references and further lectures
1) Urs Eggli “Illustrated Handbook of Succulent Plants: Dicotyledons” Springer Science & Business Media, 2002
2) “Austrobaileya”, Volume 6 Queensland Herbarium, Department of Primary Industries., 2001
3) Andrew J. Marshall, Bruce M. Beehler “The Ecology of Papua: Part Two” Tuttle Publishing, 26 June 2012
4) Maeyama, T., and T. Matsumoto. 2000. “Colonial system of Philidris ants (Formicidae; Dolichoderinae) occupying epiphytic myrmecophytes in a tropical mangrove forest.” Trop Ecol 41: 209-216.
5) Camilla R. Huxley “Ant-plant Interactions” Oxford University Press, 1991
6) Great Britain. Challenger Office, Sir Charles Wyville Thomson, Sir John Murray, George Strong Nares, Frank Tourle Thomson “Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873-76 under the command of Captain George S. Nares ... and the late Captain Frank Tourle Thomson, R.N.” Printed for H.M. Stationery off., 1885
7) Attila Kapitany “What’s new with Ant Plants?” Succulenticon 2012 - Proceedingsof the 22nd Australasian Cactus and Succulent Convention March 30th - April 2nd 2012
8) Matthew Jebb (National Botanic Gardens) Camilla Huxley (Oxford University) “A revision of the ant-plant genus Hydnophytum (Rubiaceae)” Last updated: 8th February 2009 web http://www.botanicgardens.ie/herb/research/hydnophytum.htm
9) Huxley, C.R. & M.H.P. Jebb. 1990. “New taxa in the myrmecophilous Psychotrieae (Rubiaceae).” Bull. Jard. Bot. Nat. Belg. 60: 420--421.
10) Huxley, C.R. & M.H.P. Jebb. 1991. “The tuberous epiphytes of the Rubiaceae 1: A new subtribe - The Hydnophytinae.” Blumea 36: 1-- 20.
11) Jebb, M.H.P. 1991. “Cavity structure and function in the tuberous Rubiaceae.” In C.R.Huxley & D.F.Cutler, Ant-plant Interactions: 374 --389. Oxford Univ. Press.
12) FRANK'S ANT-PLANTS “Hydnophytums: images & provenance” web: http://www.franksantplants.com/hydnophytums/

Cultivation and Propagation: Ant plants are rarely cultivated by amateur growers. These plants can be tricky to grow well and are quick to shed their leaves if they are allowed to dry out or become too cold. They needs warm temperatures all year round with high humidity and bright light, though some protection from mid-day sun may be warranted. It is possible to grow them in a mix of peat and perlite, but an open orchids substrate (sphagnum moss, chopped fir bark, and perlite) seems the best combination. The plants are watered when the mix is just barely moist. If humidity is high, plants can be mounted on cork bark plaques for a more natural appearance. Mounted plants will, of course, require more frequent watering. The roots of Hydnophytum and Myrmecodia are very brittle, so great care must be taken when repotting however, the plants seem capable of producing new roots from any part of the tuber that is in contact with a moist substrate. Hydnophytum mosleyanum can also be kept without the presence of ants, it is even strongly discouraged to let ants live in the plant when it is in the house or terrarium.
Pest and disease: Ant-plants are susceptible to scale and mealybugs.
Propagation: They are very very easy to grow from seed. The flowers are self-pollinating and produce easily fruits and seeds, but the seeds remains viable for a very short time and must be sown immediately after harvesting. The seeds germinate equally well in light and darkness, lay them on the surface of the sowing mix, do not bury them. Fresh seed germinates quickly within a week and often the day after they were sown, i.e., within twenty-four hours, and the initial swelling of the tuber is visible almost immediately. Seedlings grow rapidly if kept constantly moist. They can also be reproduced by cuttings, stems will root and grow but do not produce a tuber.