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 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 eriophora is a species of tree fern native to eastern New Guinea, where it grows in wet ravine forest at an altitude of 1400–2000 m. The trunk is erect and 2–3 m tall. Fronds are bi- or tripinnate and 2–3 m long. The stipe is dark and covered with spines and scales. The scales are variable, being either small and pale or large with a dark apex. Sori occur near the fertile pinnule midvein and lack indusia.
Cyathea ferruginea is a species of tree fern endemic to the Philippines.
Cyathea recommutata is a species of tree fern native to the Malay Peninsula, central and southern Sumatra and Borneo, where it grows in acidic peaty or sandy soils in wet forest, as well as swamp forest, from sea level to an altitude of 1500 m. The trunk is erect and rarely taller than 3 m. Fronds are bipinnate and 1–2 m long. Characteristically of this species, the lowest pair of pinnae are usually reduced and occur towards the base of the stipe. The stipe itself is dark dark and bears dark, glossy basal scales with thin, fragile edges. Fertile pinnules are notably smaller than sterile ones. Sori occur near the fertile pinnule midvein and lack indusia.
Cyathea glaberrima is a species of tree fern endemic to the D'Entrecasteaux Islands, specifically Fergusson Island and Goodenough Island, where it grows in mossy forest at an altitude of 900–1,400 m (3,000–4,600 ft). The trunk is erect and usually about 2 m tall. Fronds may be bi- or tripinnate, are 1–2 m in length, and form a dense crown. The stipe is finely warty and bears numerous glossy scales with fragile edges. Sori are produced close to the fertile pinnule midvein. They are protected by small, dark brown indusia that are scale-like in appearance.
Cyathea glabra is a species of tree fern native to Borneo, western Java, Sumatra 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.
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 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 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 propinqua is a species of tree fern native to Fiji and possibly Samoa, where it grows in wet forest. The trunk of this plant is erect and slender, growing to 10 m in height. Fronds may be bi- or tripinnate and 2–3 m long. Dull brown scales cover the dull, dark stipe of this species. The scales are minute along most of its length, becoming thick and fleshy towards the base. Sori are borne halfway between the pinnule midvein and the edge of the lobe. Indusia are present.
Cyathea horridula is a species of tree fern native to western New Guinea, where it grows in montane forest at an altitude of approximately 1700 m. It is a rare plant known only from the type locality. This plant has an erect trunk up to 3 m tall or more. Fronds may be bi- or tripinnate and 1–2 m in length. The stipe is covered with spines and bears scattered scales towards the base. These scales are pale and have fragile edges. Sori are borne near the fertile pinnule midvein. They are protected by small, dark brown 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 inquinans is a species of tree fern native to southwestern Sulawesi and possibly the Maluku Islands, where it grows in montane forest at an altitude of 2000–2800 m. This plant has an erect trunk that is usually 2–4 m tall. Fronds may be bi- or tripinnate and 1 m or more in length. The stipe is covered in scales. These scales are either large, red-brown, thin, with narrow fragile edges, or small, with a red apical seta. Sori are borne near the fertile pinnule midvein. They are protected by thin, brown indusia.
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 javanica is a species of tree fern native to western Java and Sumatra, in Indonesia.
Cyathea kanehirae is a species of tree fern native to western New Guinea, where it grows in montane forest at an altitude of 1600–2700 m. The trunk of this plant is erect and 1–4 m tall. Fronds may be bi- or tripinnate and 1–2 m in length. The rachis is smooth, while the stipe is dark and warty. The stipe is covered with flat, brown, scattered scales. Sori are borne near the fertile pinnule midvein. They are protected by small indusia that are cup-like in appearance.
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.
Cyathea latipinnula is a species of tree fern native to the Philippines, where it grows in ridge forest at an altitude of about 1400 m. The trunk of this plant is erect and grows to 1–2 m in height and 10 cm in diameter. Fronds may be bi- or tripinnate and 1–2 m in length. The stipe is spiny and bears a few narrow, brown basal scales. Sori are borne near the fertile pinnule midvein and are protected by small, dark indusia.
