''Thrixspermum congestum'', commonly known as the cupped hairseed, is an

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

lithophytic Lithophytes are plants that grow in or on rocks. They can be classified as either epilithic (or epipetric) or endolithic; epilithic lithophytes grow on the surfaces of rocks, while endolithic lithophytes grow in the crevices of rocks (and are als ...

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

that forms small clumps with many thin roots, up to fifteen leathery leaves and many star-shaped white or cream-coloured flowers. This orchid occurs from

Papuasia Papuasia is a Level 2 botanical region defined in the World Geographical Scheme for Recording Plant Distributions (WGSRPD). It lies in the southwestern Pacific Ocean, in the Melanesia ecoregion of Oceania and Tropical Asia. It comprises the ...

to northern Australia.

Description

''Thrixspermum congestum'' is an epiphytic or lithophytic

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicina ...

that forms small clumps with many thin roots and flattened stems long. It has between six and fifteen crowded stiff, leathery leaves long and wide. The flowers are cream-coloured or white, long and wide arranged on a wiry flowering stem long. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined ...

s are long and wide, the

petal Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usuall ...

s a similar length but only about . The labellum is about long and wide with three lobes. The side lobes are hairy and erect, about long and wide, narrow, curved and pointed. The middle lobe is short, fleshy and hairy with a short, hairy spur. Flowering occurs sporadically and the flowers open from one to a few at a time.

Taxonomy and naming

The cupped hairseed was first formally described in 1895 by Frederick Bailey who gave it the name ''Cleisostoma congestum'' and published the description in ''

Proceedings of the Royal Society of Queensland ''Proceedings of The Royal Society of Queensland'' is a multidisciplinary scientific journal In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new re ...

''. In 1967, Alick Dockrill changed the name to ''Thrixspermum congestum''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''congestum'') is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

word meaning "collected", "dense" or "thick".

Distribution and habitat

''Thrixspermum congestum'' grows on mangroves and rainforest trees in humid but airy situations. It occurs in

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 Torr ...

, the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its ca ...

, New Caledonia,

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...

and Australia. In Australia it is found on Melville Island and between the

Iron Range The term Iron Range refers collectively or individually to a number of elongated iron-ore mining districts around Lake Superior in the United States and Canada. Much of the ore-bearing region lies alongside the range of granite hills formed by ...

and the

Tully River The Tully River is a river located in Far North Queensland, Australia. Course and features The Tully River rises in the Cardwell Range, part of the Great Dividing Range on the northern boundary of the Kirrama State Forest. The river flows ge ...

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 , established_ ...

References

{{Taxonbar, from=Q15469147 congestum Orchids of Australia Orchids of New Guinea Plants described in 1895