Gymnosphaera annae, synonyms Alsophila annae and Cyathea annae, is a species of tree fern native Sulawesi and to Ambon in the Maluku Islands, where it grows in forest from sea level to about 650 m. The erect trunk is slender and may be as tall as 3 m. Fronds are bipinnate and 1–2 m in length. Characteristically of this species, the final pair of pinnae are usually reduced and occur towards the base of the stipe. The stipe is dark, slender and covered with scattered scales. These are dark, glossy and have a pale dull margin. Fertile pinnules are normally short-lobed. Sori lack indusia and occur two to four per pinnule lobe.
Alsophila brooksii, synonym Cyathea brooksii, is a species of tree fern native to Cuba, Hispaniola and Puerto Rico, where it grows on serpentine soils in shaded ravines, along streams, and on forested slopes at an altitude of 250–950 m. The trunk is prostrate and only about 6 cm in diameter. Fronds are pinnate or bipinnate and up to 2 m long. The base of the rachis is covered with blackish scales that have a paler margin. Sori occur in two rows, one along each side of the pinnule midvein.
Alsophila buennemeijeri, synonym Cyathea buennemeijeri, is a species of tree fern endemic to the Natuna Islands in Indonesia. In the World Geographical Scheme for Recording Plant Distributions, these islands are treated as part of Kalimantan. A. buennemeijeri grows in open scrub at an altitude of about 600 m. This rare species is known only from the summits of two low hills. The trunk is erect and may be 5 m tall or more. Fronds are bi- or tripinnate and 2–3 m long. The stipe is dark and covered with spines at the base, as well as numerous scattered dark scales with pale, fragile edges. Sori occur near the midvein of fertile pinnules and are covered by thin, fragile indusia that resemble cups in shape.
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 costularis, synonyms Cyathea chinensis and Sphaeropteris chinensis, is a species of tree fern native to Yunnan in China, Sikkim in India, as well as Nepal, Myanmar, Laos and Vietnam. Plants grow in forest and montane forest at an altitude of 900–1800 m. The trunk is erect and 1–2 m tall. Fronds are bipinnate and 1–2 m long. The stipe is either long and warty or has short spines towards the base as well as scattered glossy dark brown scales with fragile edges. Sori occur near the midvein of fertile pinnules and are covered by thin indusia.
Alsophila hermannii, synonym Cyathea christiiCopel., is a species of tree fern endemic to Mindanao in the Philippines, where it grows in forest at an altitude of 900–1800 m. The trunk is erect and may be 5 m tall or more. Fronds are bi- or tripinnate and 2–3 m long. The stipe is covered with some warts and narrow, brown scales. Sori occur near the midvein of fertile pinnules and are covered by thin, fragile indusia.
Alsophila costalisora, synonym Cyathea costalisora, is a species of tree fern native to western New Guinea, where it grows on the edges of forest and in moist hollows at an altitude of 1900–3225 m. The trunk is erect, up to 4 m tall and may branch near the base. Fronds are bi- or tripinnate and 1–1.5 m long. The stipe is warty, especially where scales have fallen. The scales are pale and have a distinctive dark glossy central region, with a paler dull margin. Sori are round and occur near the fertile pinnule midvein. They are covered by firm, dark indusia that are cup-like in appearance.
Alsophila jimeneziana, synonym Cyathea crassa, is a species of tree fern endemic to the Dominican Republic. Little is known about this rare tree fern.
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 dryopteroides, synonym Cyathea dryopteroides, is a tree fern native to Puerto Rico, where it grows in shaded areas and cloud forests at an altitude of 1000–1200 m. The erect trunk may be 1.3 m tall and approximately 5 cm in diameter. Fronds are pinnate and up to 1.6 m long. The rachis is often purplish brown and covered with scales, usually on the underside. The scales range in colour from golden brown to bicoloured. Sori occur along each side of the pinnule midvein and indusia are cup-like.
Alsophila edanoi, synonym Cyathea edanoi, is a species of tree fern endemic to Luzon in the Philippines, where it grows in montane forest at an altitude of about 1300 m. The trunk is erect and 1–2 m tall. Fronds are bi- or tripinnate and approximately 1 m long. The stipe is covered in dark, glossy scales that have narrow, fragile edges. Sori occur near the midvein of fertile pinnules and are covered, sometimes half-covered, by large, firm, brown indusia.
Gymnosphaera schliebenii, synonyms Alsophila schliebenii and Cyathea fadenii, is a species of tree fern endemic to the Uluguru Mountains in Tanzania, where it grows on exposed ridges and on the upper edge of montane forest at an elevation of 1700–2100 m. The trunk is erect, up to 4 m tall and 3–5 cm in diameter. Fronds are bipinnate. Characteristically of this species, the most basal pair of pinnae are reduced, often to veins alone.
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.
Gymnosphaera glabra, synonyms Alsophila glabra and Cyathea glabra, is a species of tree fern native to Borneo, western Java, Sumatra, the Lesser Sunda Islands, Sulawesi, and the Malay Peninsula, where it grows in lowland swamp forest and montane forest at an elevation of up to 1500 m. The trunk of this plant is erect and 2–4 m tall. Fronds are bi- or tripinnate and 1–2 m in length. Characteristically of this species, the lowest pinnae may be significantly reduced. The stipe is very dark and bears basal scales. These scales are dark, glossy and have a paler margin and fragile edges. Sori are produced in groups of one to three on fertile pinnule veins. They lack indusia.
Alsophila heterochlamydea, synonym 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.
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.
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 imbricata, synonym 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.
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.
Sphaeropteris crinita, synonyms Alsophila crinita and Cyathea crinita, is a species of tree fern native to India and Sri Lanka. It is considered to be endangered.
