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 alderwereltii is a species of tree fern endemic to Mount Sago in central Sumatra, where it is nevertheless abundant and grows in forest at an altitude of 1000–1500 m. It has an erect trunch which may be 4 m tall or more. Fronds are bi- or tripinnate and 1–2 m long. The stipe of this species is spiny at the base and covered with scattered scales that are dark brown, glossy, and have a narrow paler margin. Sori are produced near the fertile pinnule midvein and are covered by small, brown scale-like indusia.
Cyathea alleniae is a species of tree fern native to the Malay Peninsula, where it grows in forest margin on steep ground at an altitude of approximately 1200 m. The trunk is erect, about 4 m tall and 15 cm in diameter. It is usually unbranched, but may branch to form several small crowns. Fronds are bi- or tripinnate and 1–2 m long. The stipe is spiny at the base and at least partially covered by scales. Typically of section Alsophila, these scales are dark brown, glossy, and have fragile edges. Sori occur near the midvein of fertile pinnules and are covered by firm, brown indusia that resemble scales in appearance.
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 approximata is a species of tree fern endemic to Madagascar. The trunk is erect, spiny and about 2 m tall. Fronds are bipinnate and usually 2 m long. They often form a crown of two whorls of about seven fronds each. Dark brown scales with a paler margin cover the stipe. Sori are round and occur near the fertile pinnule midvein. They are covered by thin, brown indusia, which are cup-like in appearance.
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 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 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. C. brevipinna is a stunted plant with short pinnae.
Cyathea capensis is a regionally widespread and highly variable species of tree fern. It is indigenous to Southern Africa and South America.
Cyathea caudata is a species of tree fern native to the islands of Luzon and Mindanao in the Philippines, where it grows in montane forest. The trunk is erect and up to 4 m tall or more. Fronds are bi- or tripinnate and 1–2 m long. The stipe is warty and covered with dark, narrow, glossy scales. Sori are borne near the midvein of fertile pinnules and are protected by firm, brown indusia.
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.
Cyathea costulisora is a species of tree fern native to Sumatra. The trunk is erect and usually 1–4 m tall. Fronds are bi- or tripinnate and 1–2 m long. The stipe is covered with warts and scales. The scales are either pale and glossy or dark and flat. Sori occur near the fertile pinnule midvein and are covered by large, firm, brown indusia.
Cyathea cucullifera is a species of tree fern native to eastern New Guinea, where it grows in montane forest at an altitude of about 2400 m. The trunk is erect and 2–3 m tall. Fronds are bi- or tripinnate and 2–3 m long. Characteristically of this species, they occur in two whorls of four to six fronds each. The stipe is warty and covered with scales. The scales are dark, glossy, have a narrow paler margin and are large towards the base. Sori occur near the fertile pinnule midvein and are covered by thin, pale brown indusia that are scale-like in appearance.
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.
Cyathea erinacea is a species of tree fern native to Mexico, Costa Rica, Panama, Venezuela, Colombia, Ecuador, Peru and Bolivia.
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 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.
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.
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 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.
