''Hydnophytum'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of epiphytic

myrmecophyte Myrmecophytes (; literally "ant-plant") are plants that live in a mutualistic association with a colony of ants. There are over 100 different genera of myrmecophytes. These plants possess structural adaptations that provide ants with food and ...

s (ant plants) native to

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...

, the Pacific region and also extending into

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

in northern Australia. The name is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

''hydnon'' "tuber", and ''phyton'' "plant", after their appearance with their swollen succulent stems. The species grow in tree branches and on trunks. Like the related genus '' Myrmecodia'', they are known as antplants or ant-house plants. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

is ''

Hydnophytum formicarum ''Hydnophytum formicarum'', commonly called a "Baboon's head" or "Ant plant", is an epiphyte native to Southeast Asia and is considered critically endangered in Singapore. It is a myrmecophyte as ants live in its tuber, also known as a caude ...

'' from the Philippines. The genus contains 55 species, of which 44 are found in and around the island of

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...

. Many are poorly known, with 11 known only from the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

. They form a

symbiotic relationship Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

with

ants Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...

. Ant plants provide habitats for ant colonies high up into the forest canopy, protecting them from the elements and also predators because of the spines. Hollow, smooth-walled tunnels form within the

caudex A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is ...

with external entrance holes, providing an above-ground home for ant colonies. Ants likewise provide defense for the plant and prevent tissue damage, swarming to defend their home if disturbed. Ant colonies also provide nutrients to the plants by leaving wastes within the tunnels inside the caudex. Special glands lining the tunnels then absorb nutriment for the plant. This symbiosis allows the plants to effectively gather nutrients (via the ants) from a much larger area than the roots ever could cover. These plants can be grown in cultivation without the ant species being present. Two species seen occasionally in cultivation are ''

Hydnophytum ferrugineum ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' from the McIlwraith Ranges east of Coen on the Cape York Peninsula, and '' H. moseleyanum'', also from Cape York. The former has a spiny swollen trunk while the latter has a smooth one. ''Hydnophytum'' is one of five ant-plant genera in the family

Rubiaceae The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules a ...

, the others being '' Anthorrhiza'', '' Myrmecodia'', ''

Myrmephytum ''Myrmephytum'' is a genus of myrmecophytic flowering plants in the family Rubiaceae. It is distributed from central Malesia to New Guinea. It is one of five ant-plant genera in the family Rubiaceae, the others being ''Anthorrhiza'', ''H ...

'', and ''

Squamellaria ''Squamellaria'' is a genus of myrmecophytic flowering plants in the family Rubiaceae. It is endemic to the islands of Fiji. It is one of five ant-plant genera in the family Rubiaceae, the others being ''Anthorrhiza'', ''Hydnophytum'', ' ...

''.

Species

The following list, which includes more than 90 species, is based on

The Plant List The Plant List was a list of botanical names of species of plants created by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden and launched in 2010. It was intended to be a comprehensive record of all known names of plant species ...

''Hydnophytum''

. and likely includes many synonyms.

Matthew Jebb Matthew Hilary Peter Jebb (born 1958) is an Irish botanist and taxonomist specialising in the ant plant genera ''Squamellaria'', '' Myrmecodia'', '' Hydnophytum'', ''Myrmephytum'' and '' Anthorrhiza'', as well as the carnivorous plant genus '' ...

and Camilla Huxley recognise only 55 species in the genus. *''

Hydnophytum agatifolium ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' Valeton *''

Hydnophytum albense ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' Valeton *''

Hydnophytum albertisii ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

Becc. Odoardo Beccari (16 November 1843 – 25 October 1920) was an Italian botanist famous for his discoveries in Indonesia, particularly New Guinea, and Australia. He has been called the greatest botanist to ever study Malesia. His author abbrevia ...

*''

Hydnophytum alboviride ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' Merr. & L.M.Perry *''

Hydnophytum amboinense ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' Becc. *''

Hydnophytum amplifolium ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

'' S.Moore *'' Hydnophytum andamanense'' Becc. *'' Hydnophytum angustifolium'' Merr. *'' Hydnophytum archboldianum'' Merr. & L.M.Perry *'' Hydnophytum borneanum'' Becc. *'' Hydnophytum brachycladum'' Merr. *'' Hydnophytum bracteatum'' Valeton *'' Hydnophytum brassii'' S.Moore *'' Hydnophytum buxifolium'' Merr. & L.M.Perry *'' Hydnophytum caminiferum'' Wistuba, U.Zimm., Gronem. & Marwinski Wistuba, A., U. Zimmermann, D. Marwinski & T. Gronemeyer (2014). ''Hydnophytum caminiferum'', eine einzigartige neue ''Hydnophytum''-Art von der Vogelkop-Halbinsel in West Papua (Indonesien). ''

Das Taublatt ''Das Taublatt'' is a triannual German-language periodical based in Bochum and the official publication of Gesellschaft für fleischfressende Pflanzen im deutschsprachigen Raum, a carnivorous plant society based in Germany.Rice, B. 2010Carnivor ...

'' 78: 45–50. *'' Hydnophytum camporum'' S.Moore *'' Hydnophytum capitatum'' Valeton *'' Hydnophytum confertifolium'' Merr. & L.M.Perry *'' Hydnophytum contortum'' Merr. & L.M.Perry *'' Hydnophytum cordifolium'' Valeton *'' Hydnophytum coriaceum'' Becc. *'' Hydnophytum costatum'' Drake *'' Hydnophytum crassicaule'' P.Royen *'' Hydnophytum crassifolium'' Becc. *'' Hydnophytum cuneatum'' Valeton *'' Hydnophytum decipiens'' Merr. & L.M.Perry *'' Hydnophytum dipteropodum'' (K.Schum. & Lauterb.) Valeton *'' Hydnophytum dolichophyllum'' Valeton *'' Hydnophytum ellipticum'' Merr. & L.M.Perry *''

'' P.I.Forst. *'' Hydnophytum forbesii'' Hook.f. *''

'' Jack *'' Hydnophytum grandiflorum'' Becc. *'' Hydnophytum grandifolium'' Valeton *'' Hydnophytum guppyanum'' Becc. *'' Hydnophytum hahlii'' Rech. *'' Hydnophytum hellwigii'' Warb. *'' Hydnophytum heterophyllum'' Merr. & L.M.Perry *'' Hydnophytum inerme'' (Gaudich.) Bremek. *'' Hydnophytum intermedium'' Elmer *'' Hydnophytum kajewskii'' Merr. & L.M.Perry *'' Hydnophytum kejense'' Becc. *'' Hydnophytum kelelense'' Valeton *'' Hydnophytum kochii'' Valeton *'' Hydnophytum lanceolatum'' Miq. *'' Hydnophytum laurifolium'' Warb. *'' Hydnophytum lauterbachii'' Valeton *'' Hydnophytum ledermannii'' Valeton *'' Hydnophytum leytense'' Merr. *'' Hydnophytum linearifolium'' Valeton *'' Hydnophytum longiflorum'' A.Gray *'' Hydnophytum longipes'' Merr. & L.M.Perry *'' Hydnophytum longistylum'' Becc. *'' Hydnophytum loranthifolium'' (Benth.) Becc. *'' Hydnophytum lucidulum'' Valeton *'' Hydnophytum macrophyllum'' Warb. *'' Hydnophytum magnifolium'' Merr. & L.M.Perry *'' Hydnophytum membranaceum'' Merr. *'' Hydnophytum microphyllum'' Becc. *'' Hydnophytum mindanaense'' Elmer *'' Hydnophytum mindorense'' Merr. *'' Hydnophytum montis-kani'' Valeton *''

Hydnophytum moseleyanum ''Hydnophytum'' is a genus of epiphytic myrmecophytes (ant plants) native to Southeast Asia, the Pacific region and also extending into Queensland in northern Australia. The name is derived from the Ancient Greek ''hydnon'' "tuber", and ''ph ...

Notes

{{Taxonbar, from=Q291522 Rubiaceae genera Myrmecophytes Epiphytes Psychotrieae