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 acanthophora is a species of tree fern endemic to Kinabalu National Park in Borneo, where it grows in montane rain forest at an altitude of 1250–2000 m. The trunk is erect and can grow as tall as 5 m or higher. Fronds are 2–3 m in length and bi- or tripinnate. The stipe is dark towards the base and has slender spines. It is covered with scattered scales, which are glossy brown and have a narrow paler margin. Sori occur near the midvein of fertile pinnules. They are covered in thin, fragile indusia, which resemble small saucers.
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 apoensis is a species of tree fern native to Mindanao, Negros and southern Luzon in the Philippines, where it grows in dense forest at an altitude of approximately 1800 m. The trunk is erect and 2–5 m tall. The rachis is dark and warty. The stipe is covered with scattered scales, which are either large, dark and glossy, or small and dull brown. Sori are round and occur near the fertile pinnule midvein. They are covered by thin, brown, cup-like indusia.
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 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 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 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.
Cyathea christii 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.
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 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.
Cyathea doctersii is a species of tree fern endemic to Sumatra, where it grows in forest at an altitude of approximately 150 m. The trunk is erect and 2–3 m tall. Fronds are bi- or tripinnate and 2–3 m long. The stipe is covered with scattered flat, brown scales and some hairs. Sori occur near the fertile pinnule midvein and are covered by thin, brown indusia that are scale-like in appearance.
Cyathea ferruginea is a species of tree fern endemic to the Philippines.
Cyathea halconensis is a species of tree fern native to the islands of Luzon and Mindoro in the Philippines, where it grows in forest at an altitude of 1200–1700 m. The trunk of this plant is erect and 2–4 m tall. Fronds may be bi- or tripinnate and more than 1 m in length. Conical spines and scales cover the stipe. These scales are dark brown in colouration and have fragile edges. Sori occur near the fertile pinnule midvein. They are protected by thin, pale 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 hookeri is a species of tree fern endemic to Sri Lanka, where it grows in lowland forest. This plant has a narrow, erect trunk that is usually 1–2 m tall. Fronds are pinnate and approximately 1 m in length. The stipe is dark and covered with blunt spines and scattered scales. These scales are long, glossy, medium brown in colouration, and have fragile edges. Sori are borne on the lowest one or two pairs of veins of fertile pinnules. They are protected by thin indusia.
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.
Cyathea insulana is a species of tree fern native to New Guinea, where it grows in mossy forest and ravines at an altitude of 750–1600 m. The trunk of this species is erect, 8–10 m tall, and 14 cm in diameter. Fronds may be bi- or tripinnate and approximately 3 m in length. They form a spreading crown. The stipe bears thick spines as well as scales. These scales are either small, pale brown, with a short fringe, or large and glossy brown, with fragile edges. Sori are borne near the fertile pinnule midvein. They are protected by thin, pale indusia.
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 lepidoclada is a species of tree fern native to central and eastern New Guinea, where it is locally common in rain forest and mossy forest at an altitude of 200–1000 m. The trunk of this species is erect and usually 2–3 m tall. Fronds are bipinnate, about 1.5 m in length, and form a sparse crown. The stipe bears blunt spines and scales towards the base. These scales are glossy, dark brown in colouration, and have a paler, thin margin. The round sori are borne in groups of four to five per fertile segment. They are covered by deep, firm indusia that are cup-like in appearance.
