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.
Alsophila archboldii, synonym 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.
Alsophila australis, synonym 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.
Alsophila brevipinna, synonym Cyathea brevipinna, is a species of tree fern endemic to the higher parts of Mount Gower on Lord Howe Island, where it grows in exposed areas at an altitude of about 790 m. The trunk is erect and may reach 3 m in height. It is often covered with reddish brown scales and stipe bases. This species may produce stolons at ground level. Fronds are tripinnate, densely crowded, and up to about 3 m long. The stipe is brown and sometimes warty after scales fall off. The scales are long, glossy dark brown, with a distinctly narrow apex and fragile paler edges. Sori are attached to deeply divided fertile pinnules that may uncurl over the sori. Indusia are firm and large. A. brevipinna is a stunted plant with short pinnae.
Alsophila camerooniana, synonym 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.
Alsophila capensis, synonym Cyathea capensis, is a regionally widespread and highly variable species of tree fern. It is indigenous to Southern Africa and South America.
Alsophila cunninghamii, synonym Cyathea cunninghamii, also known as the gully tree fern and slender tree fern, is a species of tree fern indigenous to New Zealand including North Island, South Island and Chatham Islands; also to Victoria, possibly New South Wales, southeastern Queensland and Tasmania in Australia. It grows in damp forest, often emerging from stream gullies and riverbanks. Brownsey noted that it has a lower tolerance for drought than other related species. The erect trunk may be 20 m tall and is usually 6–15 cm in diameter, occasionally as much as 20 cm. Fronds are tri- to tetrapinnate and 3 m or more in length. The rachis and stipe are slender, black brown, warty and covered with brown scales. Sori occur along each side of the pinnule midvein and are covered by hood-like indusia. A. cunninghamii is an uncommon and slow-growing tree fern.
Alsophila deckenii, synonym Cyathea deckenii, is a species of tree fern native to the Democratic Republic of the Congo, Tanzania and Mozambique, where it grows in wet forest at an altitude of 1350–2300 m. The trunk is erect and up to 10 m tall. Fronds are bipinnate and 2–3 m long. Characteristically of this species, the most basal one or two pairs of pinnae are reduced. The rachis and stipe range in colour from brown to dark brown or black-brown and are sparsely covered with a few scales. The scales are dark and narrow with a fragile margin of variable width. The stipe also has conical warts near the base. Sori are round and covered by large, thin indusia.
Alsophila dregei, synonym Cyathea dregei, is a widespread species of tree fern in southern Africa.
Alsophila fenicis, synonym Cyathea fenicis, is a species of tree fern native to the Philippines, Taiwan, and Orchid Island, where it grows in wet forest, forest margins and on hillsides. The trunk is erect, up to 1 m tall and about 6 cm in diameter. Fronds are tripinnate and 1.5–2 m long. Characteristically of this species, the lowest pinnae are usually reduced. The stipe is spiny and ranges in colour from brown to purple-dark brown. It bears two types of scales: long dark brown scales as well as minute brown ones. Occasionally the scales are pale. Sori are round and arranged in two rows, one on either side of the pinnule midvein. They are covered by very small indusia that resemble scales in appearance.
Alsophila gregaria, synonym Cyathea gregaria, is a species of tree fern endemic to eastern New Guinea, where it grows in lowland forest and coastal rain forest, often forming clumps, at an elevation of up to 100 m. The trunk of this plant is erect and usually 4–5 m tall and about 10 cm in diameter. Fronds may be bi- or tripinnate and 2–3 m in length. The stipe bears spines, but has few scales. These scales are medium brown in colouration and have a paler margin. Sori occur near the fertile pinnule midvein and lack indusia.
Alsophila grevilleana, synonym 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.
Alsophila acaulis, synonym Cyathea hancockii, is a species of tree fern native to the Ryukyu Islands, Japan, Taiwan and Hong Kong. The specific epithet hancockii commemorates William Hancock (1847-1914), who collected numerous plants in Japan, China and Southeast Asia. It grows in forest, on stream banks, and in forest margins at an elevation of about 600 m or higher.
Alsophila hooglandii, synonym Cyathea hooglandii, is a species of tree fern native to the Western Highlands of New Guinea, where it grows in mossy forest at an altitude of about 3000 m. The trunk of this plant is erect, up to 3 m tall and approximately 10 cm in diameter. Fronds are tripinnate, 1–2 m in length and produced in two whorls of five to seven each. The stipe may be dull and warty or densely covered with scales. These scales range in colour from dark to medium brown and have a broad, paler margin as well as fragile edges. Perhaps the most distinguishing feature of this species are its sori, which are borne singly at the base of each tertiary pinnule on the midvein. They are protected by firm indusia that are saucer-like in appearance.
Alsophila × marcescens, synonym 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 Alsophila australis × Alsophila cunninghamii. Large and Braggins (2004) note that it has characteristics midway between these two species. The spores of A. × 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.
Sphaeropteris elmeri, synonym Cyathea elmeri, is a species of tree fern native to the Philippines, Talaud Islands, and northern Sulawesi, where it grows in forest at an altitude of 500–1400 m. The trunk of this plant is erect and 5–10 m tall. Fronds may be bi- or tripinnate and up to 2 m or more in length. The lower surface of the rachis is distinctively pale and warty. The stipe is covered with scales and has warts towards the base. The scales are large, tapering, thin, and medium brown in colouration. Sori are borne near the fertile pinnule midvein. Indusia are absent.
Alsophila metteniana, synonym Cyathea metteniana, is a species of tree fern native to the Ryukyu Islands, Japan, and Taiwan, where it grows in wet forest, forest margins, and on hillsides. The trunk of this plant is erect, up to 1 m tall, and 6–10 cm in diameter. C. metteniana has tripinnate fronds that are 1–2.5 m long. The stipe is brown to purple-black in colouration. It is covered in long, broad-based scales that are usually bicoloured. Sori are round, lack indusia, and occur in two rows, one on either side of the pinnule midvein.
Alsophila humilis, synonym 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, 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.
Alsophila kermadecensis, synonym Cyathea kermadecensis, is a species of tree fern endemic to Raoul Island in the Kermadec Islands, where it is locally common in damp, and sometimes drier, forest and scrub. The trunk of this plant is erect, slender, and up to 20 m tall. It is often covered with scars of old stipe-bases. Fronds are tripinnate and up to 4 m in length. The rachis and stipe are both brown in colouration and bear basal scales that are brown, glossy, and often twisted. Sori are borne on either side of the pinnule midvein. They are covered by hood-like indusia.
Alsophila latebrosa, synonym 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. A. 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.
