Cyathea humilis | |
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Scientific classification | |
Kingdom: | Plantae |
Division: | Pteridophyta |
Class: | Pteridopsida |
Order: | Cyatheales |
Family: | Cyatheaceae |
Genus: | Cyathea |
Subgenus: | Cyathea |
Section: | Alsophila |
Species: | C. humilis |
Binomial name | |
Cyathea humilis Hieronymus in Engler & Prantl, 1895 | |
Varieties | |
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Synonyms | |
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Cyathea humilis is a species of tree fern native to Kenya, as well as the Usambara and Uluguru Mountains in Tanzania, where it grows in wet forest at an altitude of 1100–2000 m. The trunk of this plant is erect and 2–3 m tall. Fronds are pinnate and 1–2 m in length. Dead fronds are often retained in the typical variety (C. h. var. humilis), forming an irregular skirt around the trunk. The rachis and stipe are light brown in colouration. Scales are present towards the base of the stipe. They are dark, glossy, and have narrow, fragile edges. Sori occur at the forks of veins and are protected by thin, reduced indusia.
The order Cyatheales, which includes the tree ferns, is a taxonomic division of the fern class, Polypodiopsida. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicate the order is monophyletic. Some species in the Cyatheales have tree-like growth forms, but others have rhizomes.
Kenya, officially the Republic of Kenya, is a country in Africa with 47 semiautonomous counties governed by elected governors. At 580,367 square kilometres (224,081 sq mi), Kenya is the world's 48th largest country by total area. With a population of more than 52.2 million people, Kenya is the 27th most populous country. Kenya's capital and largest city is Nairobi while its oldest city and first capital is the coastal city of Mombasa. Kisumu City is the third largest city and a critical inland port at Lake Victoria. Other important urban centres include Nakuru and Eldoret.
The Usambara Mountains of northeastern Tanzania in tropical East Africa, comprise the easternmost ranges of the Eastern Arc Mountains. The ranges of approximately 90 kilometres (56 mi) long and about half that wide, are situated in the Lushoto District of the Tanga Region. They were formed nearly two million years ago by faulting and uplifting, and are composed of Precambrian metamorphic rocks. They are split into two sub-ranges; the West Usambaras being higher than the East Usambaras, which are nearer the coast and receive more rainfall.
Two distinct varieties of C. humilis are known. C. h. var. pycnophylla, the lesser known form, is endemic to the Mogodoro district of Tanzania. This variety differs in the shape of its fronds and does not retain them as a skirt around its trunk. Further study is needed to more precisely determine the taxonomic status of these plants.
In biology, taxonomy is the science of defining and naming groups of biological organisms on the basis of shared characteristics. Organisms are grouped together into taxa and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a super-group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum, class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the father of taxonomy, as he developed a system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms.
Large and Braggins (2004) note that the holotype of C. humilis is "almost certainly a juvenile of Cyathea stuhlmannii", a taxon also described by Hieronymus. Since the specific epithet humilis is older, it takes precedence, and C. stuhlmannii should be regarded as a junior synonym.
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN the definitions of types are similar in intent but not identical in terminology or underlying concept.
Hieronymus, in English pronounced or, is the Latin form of the Ancient Greek name Ἱερώνυμος (Hierṓnymos), meaning "with a sacred name". It corresponds to the English given name Jerome.
An epithet is a byname, or a descriptive term, accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, divinities, objects, and binomial nomenclature. It can also be a descriptive title: for example, Pallas Athena, Alfred the Great, Suleiman the Magnificent or Władysław I the Elbow-high.
Cyathea affinis is a variable species of tree fern native to Fiji, Samoa, the Cook Islands, Austral Islands, Tahiti, and the Marquesas Islands. The trunk of this plant is erect and 2–6 m tall. Fronds are bipinnate and 2–3 m in length. The rachis and stipe are pale to brown in colour, or flushed with red towards the pinnule rachis. The stipe is sparsely covered in narrow basal scales, which are pale to dark and have broad fragile edges. Characteristically of this species, the lowest one or two pairs of pinnae may be slightly reduced and occur towards the base of the stipe. Sori are located near the pinnule midvein and are partially or fully covered by indusia, which open towards the pinnule margin.
Cyathea alpicola is a species of tree fern native to central Sumatra, where it grows in montane rain forest at an altitude of 2000–2750 m. The erect trunk can reach 5 m or more in height. Fronds are bi- or tripinnate and usually 2–3 m long. They have a tendency to persist on the plant after withering, forming an irregular skirt around the trunk. This species has a spiny stipe, which is covered with a woolly layer of scales. There appear to be two forms with different scales; either dark glossy brown with a broad paler margin and fragile edges, or small, brown and finely fringed. Sori are covered by thin, fragile indusia and occur near the midvein of fertile pinnules. The closest relative of C. alpicola is thought to be Cyathea polycarpa, which differs by lacking spines altogether. Cyathea macropoda and Cyathea magnifolia may also be closely allied with this species.
Cyathea archboldii is a species of tree fern native to New Guinea and Bougainville, where it is common in submontane rain forest at an altitude of 1000–3000 m. The trunk is erect and up to about 3 m tall. Fronds are bipinnate and 2–3 m long. The rachis may be purplish and has short spines and scales. The scales range in colour from pale to brown, to bicoloured and have fragile edges. Sori occur in two rows along each side of the pinnule midvein and are covered by firm indusia.
Cyathea atropurpurea is a species of tree fern native to the islands of Luzon, Mindanao, Leyte and Mindanao in the Philippines, where it grows in forest at above 1000 m. The erect trunk is slender and may be up to 3 m tall. Fronds are bipinnate and 1–2 m long. Characteristically of this species, the final pair of pinnae are usually reduced and occur towards the base of the stipe. These, along with the stipe bases, are persistent and retained around the trunk long after withering. The stipe itself is dark and covered with scales, which are either small, dull and brown or large, dark and glossy. Sori occur near the midvein of fertile pinnules and lack indusia. Fertile pinnules are notably smaller than sterile ones.
Cyathea australis, also known as the Rough Tree Fern, is a species of tree fern native to southeastern Queensland, New South Wales and southern Victoria in Australia, as well as Tasmania and Norfolk Island.
Cyathea baileyana, also known as the wig tree fern, is a species of tree fern native to northeastern Queensland in Australia, where it grows in wet gullies and forest at an altitude of 850–1200 m. It is a rare species that is seldom found in the wild. The erect trunk is 4–5 m tall, approximately 10 cm in diameter and may be covered in stipe bases in the upper regions. C. baileyana is notable for being able to develop offshoots from the base of the trunk. Fronds are bi- or tripinnate and may be exceptionally long, up to 7 m, though they are usually around 2–3 m. The rachis and stipe are dark to darkish red, scaly and may be warty, but lack spines. Scales on the rachis and stipe are purplish brown to black and have a long hair-like apex. Characteristically of this species, the last pair of pinnae are separated from the others along the rachis and may form a clump around the trunk apex. Sori are circular and occur in one to three rows along the pinnule midvein. They lack indusia.
Cyathea camerooniana is a species of tree fern native to Sierra Leone, Cameroon, northern Angola and western Uganda, where it grows in montane forest at an altitude of 900–1200 m. The trunk is erect and 2–3 m tall. Fronds are pinnate and 2–3 m long. The rachis ranges in colour from dark to pale and has some hairs on the underside. The stipe is dark and is covered with scales throughout. Where scales have fallen, small warts are present. The scales are glossy brown and have a thin, dull edge. Sori occur at the forks of veins and are covered by thin indusia, which range in shape from cup- to saucer-like.
Cyathea catillifera is a species of tree fern native to eastern New Guinea, where it grows in montane scrub at an altitude of about 2800 m and above. It is a rare plant, known only from the type locality. The erect trunk is up to about 1 m tall and 10 cm in diameter. Characteristically of this species, the trunk often branches at the base. Fronds are bi- or tripinnate, 1–2 m long and may bear a pair of reduced pinnae towards the base. There are usually around six live fronds per crown at any one time. The stipe is spiny, warty and pale on the upper surface to dark at the base. It is |covered with scattered basal scales that are glossy dark brown and have a paler margin. Stipes are persistent with bases retained on the trunk. Sori occur near the midvein of fertile pinnules and are covered by thin, brown indusia that are saucer-like in appearance.
Cyathea excavata is a species of tree fern endemic to the Cameron Highlands in Peninsular Malaysia, where it grows in habitats ranging from forest, streamsides, clearings and open grassy areas at an altitude of approximately 1800 m. The trunk is erect and up to 2 m tall or more. It forms lateral shoots. Fronds are bi- or tripinnate and about 2 m long. They are persistent and may be retained forming a characteristic skirt around the trunk. The stipe is smooth, green and covered with dull, thin basal scales. Sori occur near the fertile pinnule midvein and are covered by pale, thin indusia that are saucer-like in appearance.
Cyathea gleichenioides is a species of tree fern endemic to New Guinea, where it grows in open peaty grassland and on forest margins, often in groups, at an altitude of 2800–3700 m. The trunk of this plant is erect, up to 3 m tall and about 24 cm in diameter. The narrow fronds are tripinnate and about 1 m in length. Around 60 fronds form a rounded crown.The stipe is warty and bears scattered scales towards the base. These scales may be either glossy brown with a paler dull margin, or small, pale and fringed. Sori occur one or two per fertile pinnule and are protected by firm, brown indusia.
Cyathea grevilleana is a species of tree fern endemic to Jamaica, where it grows in moist gullies and on wooded hills in both calcareous and noncalcareous soils at an altitude of 200–1200 m. The trunk of this plant is erect, about 7 m tall, and 10–15 cm in diameter. It is characteristically clothed in old stipe bases, brown scales and blackish spines. Fronds are tripinnate, dark green in colour, and up to 4 m in length. The last pinnae are sometimes separated, forming a distinctive clump around the trunk apex. The rachis is yellow-brown and almost smooth. This species has a long, dark brown stipe with a few scattered spines. Sori are produced in four to six pairs along the pinnule midvein. They are protected by pale brown indusia that are cup-like in appearance.
Cyathea heterochlamydea is a little-known species of tree fern native to the islands of Luzon, Panay, Negros and Mindanao in the Philippines, where it grows in montane forest. The trunk of this plant is erect and usually up to 4 m tall or more. Fronds may be bi- or tripinnate and 1–2 m in length. The stipe is warty and/or bears short spines and scales. These scales are dark, glossy and have a narrow pale margin. Sori are borne near the fertile pinnule midvein and are protected by firm, brown indusia.
Cyathea × marcescens, commonly known as the skirted tree fern, is a tree fern endemic to the Cape Otway ranges in Victoria and Tasmania, Australia. It is a natural hybrid, apparently Cyathea australis × Cyathea cunninghamii. Braggins and Large (2004) note that it has characteristics midway between these two species. The spores of C. × marcescens are usually malformed although sterile. The trunk of this plant is erect and up to 10 m tall. Fronds may be bi- or tripinnate and 3–4 m in length. Dead fronds often persist, forming a characteristic skirt around the trunk. The stipe is thick, black and warty. The rachis and trunk are covered in shiny, dark brown scales. Sori are borne near the fertile pinnule midvein and are protected by thin indusia that are saucer-like in appearance.
Cyathea hunsteiniana is a species of tree fern endemic to eastern New Guinea, where it grows in rain forest at an altitude of 1300–2000 m. This species has a slender, erect trunk up to 1 m tall and about 3 cm in diameter. Fronds are bipinnate and approximately 1 m in length. Scattered scales cover the stipe. They are dark brown in colouration and have a broad paler margin and fragile edges. Round sori are borne one or two per fertile pinnule segment. The sori are protected by deep, firm indusia that are cup-like in appearance.
Cyathea imbricata is a species of tree fern endemic to Western New Guinea, where it grows in open forest at an altitude of 3240 m. The trunk of this plant is erect and approximately 2 m tall. Fronds may be bi- or tripinnate and are usually less than 1 m in length. The stipe is dark, spiny, and covered with caducous scales. These scales are glossy brown in colouration and have a paler margin and fragile edges. Sori are borne in groups of one to four per pinnule lobe. They are protected by firm indusia.
Cyathea incisoserrata is a species of tree fern native to the Malay Peninsula and the state of Sarawak on the island of Borneo, where it grows in forest and forest margins from the lowland to approximately 1250 m. The trunk is erect, about 4 m tall and 12 cm in diameter. Fronds may be bi- or tripinnate and 1–2 m in length. The stipe of this species is partly persistent and is sometimes retained on the upper trunk. It is warty, bears conical spines, and is sparsely covered with scales. These scales may be either small and fringed or bullate. Sori are borne near the fertile pinnule midvein. They are protected by very small, often bilobed indusia.
Cyathea javanica is a species of tree fern native to western Java and Sumatra, in Indonesia.
Cyathea junghuhniana is a species of tree fern native to southern and central Sumatra and western Java, where it grows in forest at an altitude of 1000–2000 m. The trunk of this species is erect and may be 2 m tall or more. Fronds are tripinnate and up to about 3 m long. The stipes of this species are persistent and form a skirt around the trunk. They are brown, spiny, and covered with glossy, dark brown scales. Sori are borne near the midvein of fertile pinnules and are protected by thin indusia.
Cyathea latebrosa is a common and widespread species of tree fern native to Indochina. Its natural range covers Cambodia and Thailand, and stretches from the Malay Peninsula to Indonesia, where it is present on the islands of Borneo and Sumatra. Plants reported from India and Sri Lanka have thinner indusia and may represent a separate, as-yet undescribed, species. C. latebrosa grows in a wide range of habitats, including forest, secondary forest, and plantations, from sea level up to an elevation of about 1500 m.
Cyathea smithii, commonly known as the soft tree fern or kātote, is a species of tree fern from New Zealand.
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