Helicia | |
---|---|
Helicia ceylanica | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Subfamily: | Grevilleoideae |
Tribe: | Roupaleae |
Subtribe: | Heliciinae |
Genus: | Helicia Lour. |
Type species | |
Helicia cochinchinensis |
Helicia is a genus of 110 species of trees and shrubs, constituting part of the plant family Proteaceae. [3] They grow naturally in rainforests throughout tropical South and Southeast Asia, including India, Sri Lanka, Indochina, Peninsular Malaysia to New Guinea and as far south as New South Wales.
At global, national and regional government scales, many Helicia species have been threatened with extinction, as officially recognised by the International Union for Conservation of Nature (IUCN) and by continental, national and local governments. Sixteen species have official IUCN global conservation statuses of either "critically endangered", "endangered", "vulnerable" or "near threatened" (in terms of global extinction).
In 1790, notable pioneer botanist João de Loureiro described this genus as Helicia in his publication Flora Cochinchinensis . [1] [2] The type species for the genus was Helicia cochinchinensis, the type specimen of which was collected in Cochinchina, Vietnam. [1] [2] The genus name derives from the Greek word "έλιξ" (élix), which refers to the petals, now called tepals, spirally revolving or simply rolling or coiling up on themselves, at anthesis (the flowering time when the anthers open). [1] [4] [5]
In 1831, botanist Nathaniel Wallich named Helicia robusta for a dried specimen of a cultivated plant in India, [6] based on the specimen's earlier 1814 name Roupala robusta by William Roxburgh. [7] Roxburgh's Calcutta botanic gardens cultivated the plant.
From the 1850s to the 1860s notable German–Australian botanist Ferdinand von Mueller formally described several new Australian species. [8] [9] [10] In the late 1800s and early 1900s Frederick M. Bailey concentrated further on additional Queensland species, writing descriptions of them in numerous scientific papers. [11] [12] [13]
In 1939, Hermann O. Sleumer described many additional Malesian species, especially in New Guinea. [14] In 1955, he published a revision of the genus. [15] In 1956, his treatment of the genus in Flora Malesiana was published. [16] From 1969 to the late 1990s botanist Don B. Foreman, who was based in Papua New Guinea and Australia, collected numerous additional species, which he formally described before he wrote the comprehensive reviews and flora treatments for the two regions; [17] [18] [19] [20] notably in the authoritative Handbooks of the Flora of Papua New Guinea (1978–1995, to date 3 volumes), he wrote the chapters for Proteaceae and other families; [21] and in the authoritative Flora of Australia (1981–, 60 volume series) he wrote the treatment of Helicia. [4]
From the 1990s botanist Richard C. K. Chung, based in Malaysia, published new species formal descriptions and a revision of the 13 species occurring in Borneo. [22] [23] In total, approximately 100 species have been formally scientifically described. [24] [25] [26]
Lawrie Johnson and Barbara G. Briggs grouped Helicia with Xylomelum in the subtribe Heliciinae, tribe Helicieae, and subfamily Grevilleoideae in their 1975 monograph "On the Proteaceae: the evolution and classification of a southern family". [27] However, genetics studies showed these two to be relatively unrelated, instead finding the closest genetic correlations between Hollandaea and Helicia, and therefore classifying them both in the subtribe Heliciinae within the tribe Roupaleae. [24]
Helicia plants generally grow naturally as small trees, while some species grow as shrubs and some grow to medium-sized trees up to 30 m (100 ft). [16] [21] [28]
They grow naturally across the Malesia region with the major centre of species diversity of about fifty species in New Guinea. They grow naturally in the south west Pacific ocean region, and in north and eastern Australia. They grow naturally across southern and eastern Asia, including Indonesia, Malaysia and another centre of species diversity of about twenty species in southern China, extending to parts of the Indian subcontinent, the Philippines, Taiwan, and southern Japan. [16] [21] [24] The plant family Proteaceae's 1,700 species (approximate) have their greatest diversity in the southern hemisphere and smaller centres of diversity including some Helicia, in the near northern hemisphere. The species diversity of the plant family Proteaceae decreases further northwards. H. cochinchinensis has the natural distribution reaching furthest north to Japan where it grows into trees in the mountains of warmer parts and where no other species nor other Proteaceae genera occur. The same Japanese name Yama-mogashi (山もがし) for this species, also means the whole genus and the entire Proteaceae plant family. [29] In the New Guinea and southern China centres of species diversity, many species grow in forests, up to as tall as the sub-canopy, especially diverse in rainforests. [21] [24] In Australia, they are generally components of rainforests, and prefer richer soils, [28] especially in the farthest south region of Helicia's global distribution, the Illawarra, New South Wales, south of Sydney, where only one species H. glabriflora occurs, preferring richer basalt soils. [30] [31]
In India and east Asia Helicias have been cultivated in botanic gardens, from the 1800s. [7] In Australia they have rarely been cultivated, and were thought to have little horticultural value. The rusty-coloured new growth is attractive on some species. [28] In some of the better known Australian species, the flowers and fruit are generally not prominent, and plants can be slow growing. They are generally propagated by seed, the viability of which drops rapidly with time. [32]
(this list may have a small number of species missing, presently it has 99, out of the approximate total stated by sources of 110)
Athertonia is a genus of tall trees, constituting part of the plant family Proteaceae. It is a monotypic taxon, and the sole described species is Athertonia diversifolia, commonly known as Atherton oak. It is a small to medium-sized tree and is endemic to restricted tablelands and mountainous regions of the wet tropics rain forests of north-eastern Queensland, Australia, where it is widespread. For example, it grows in the Atherton Tableland region with which it shares its name, from the colonial pastoralist John Atherton (1837–1913). Its closest relatives are Heliciopsis and Virotia. A relative of the macadamia, it has potential as an ornamental tree and has an edible nut.
Triunia is a genus of medium to tall shrubs or small trees found as understorey plants in rainforests of eastern Australia. Members of the plant family Proteaceae, they are notable for their poisonous fleshy fruits or drupes. Only one species, T. youngiana, is commonly seen in cultivation.
Alloxylon brachycarpum is a species of plant in the family Proteaceae. It is found in Indonesia and Papua New Guinea. It is threatened by habitat loss.
Helicia albiflora is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia amplifolia is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia australasica, also named Austral oak or creek silky oak, is a species of rainforest trees from the flowering plant family Proteaceae.
Helicia calocoma is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia insularis is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia latifolia is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia neglecta is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia peltata is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Helicia polyosmoides is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss. This taxon was described by Don Foreman in 1985.
Helicia retusa is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea.
Helicia subcordata is a species of plant in the family Proteaceae. It is endemic to Papua New Guinea. It is threatened by habitat loss.
Heliciopsis is a genus of about thirteen species of trees, constituting part of the flowering plant family Proteaceae. They grow naturally in Burma, Indo-China, SE. China, Thailand, Peninsular Malaysia, Borneo, Sumatra, Java (Indonesia) and the Philippines. The name means similar to the plant genus Helicia. Its closest relatives are Athertonia (Australia) and Virotia.
Helicia glabriflora is a species of rainforest shrubs or small trees occurring in eastern Australia. Common names include smooth or pale helicia, pale, leather or brown oak. They grow naturally in a variety of different rainforest types from the Illawarra, New South Wales to the Townsville area, Queensland. Of all the global diversity of approximately one hundred Helicia species, this one species naturally grows the furthest south, in the Minnamurra Rainforest and the Robertson area, Illawarra, New South Wales, there observed more on the relatively fertile basalt and alluvial soils.
Helicia recurva is a species of rainforest trees, of northeastern Queensland, Australia, from the flowering plant family Proteaceae.
Helicia blakei, also named Blake's silky oak, is a species of rainforest tree, of northeastern Queensland, Australia, from the flowering plant family Proteaceae.
Helicia nortoniana, also named Norton's silky oak, is a species of rainforest trees, of northeastern Queensland, Australia, from the flowering plant family Proteaceae.
Don Foreman was an Australian botanist who worked on the Monimiaceae and Proteaceae of Australia. He also helped with the editing of selected Flora of Victoria and Flora of Australia Volumes.
Helicia (100)
Helicia Lour. Proteaceae (V 1). c. 100 Indomal., Pac.