Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
Cycas pruinosa is a small to medium species of cycad, a palm-like seed plant. It is a widespread but sporadic species in the eastern and southern Kimberley region of Western Australia, occurring also in the Spirit Hills on Bullo River Station in the Northern Territory.
Cycas is a genus of cycad, and the only genus in the family Cycadaceae. About 113 species are accepted, which are native to the Indo-Pacific, East Africa and Madagascar. Cycas circinalis, a species endemic to India, was the first cycad species to be described in western literature, and is the type species of the genus. The best-known Cycas species is Cycas revoluta.
Cycas revoluta is a species of gymnosperm in the family Cycadaceae, native to southern Japan including the Ryukyu Islands. It is one of several species used for the production of sago, as well as an ornamental plant. The sago cycad can be distinguished by a thick coat of fibers on its trunk. The sago cycad is sometimes mistakenly thought to be a palm, although the only similarity between the two is that they look similar and both produce seeds.
Cycas angulata is a species of cycad in the genus Cycas, native to Australia in northeast Northern Territory and northwest Queensland.
Cycas armstrongii is a species of cycad in the genus Cycas, endemic to Northern Territory of Australia. It is found from the Finniss River in the west to the Arnhem Highway in the east, north of Pine Creek. It also occurs on the Tiwi Islands and the Cobourg Peninsula
Cycas arnhemica is a species of cycad in the genus Cycas, native to Australia, in the northwest of Northern Territory in Arnhem Land, after which it is named.
Cycas badensis is a species of cycad in the genus Cycas, native to Australia, in the extreme north of Queensland, where it is endemic on Badu Island in the Torres Strait Islands.
Cycas basaltica is a species of cycad in the genus Cycas, native to Australia, in the far north of Western Australia in the Kimberley region.
Cycas beddomei is a species of cycad in the genus Cycas, native to India, where it is confined to a small area of Andhra Pradesh state in the Tirumala Hills in scrubland and brush covered hills.
Cycas brunnea is a species of cycad in the genus Cycas, native to northern Australia in northwest Queensland and northeast Northern Territory in a small area straddling the border of the two regions. It occurs on exposed sites in savanna and creek valleys on sandstone and limestone derived soils, with moderate seasonal rainfall.
Cycas cairnsiana is a species of cycad in the genus Cycas, native to northern Australia in northern Queensland on the Newcastle Range.
Cycas chamaoensis is named after the only known habitat of this species, on and near Khao Chamao mountain in Khao Chamao District, Thailand. Stems are arborescent, either erect or decumbent. Leaves numerous, exceeding 60 per crown, 1.2-2.5 meters in length, ending in terminal spine. Petiole 30–60 cm, glabrous and partially spiny. Leaflets in 85-155 pairs, and lanceolate, glabrous and angled forward at 60-70 degrees.
Cycas micronesica is a species of cycad found on the island of Yap in Micronesia, the Marianas islands of Guam and Rota, and The Republic of Palau. It is commonly known as federico nut or fadang in Chamorro. The species, previously lumped with Cycas rumphii and Cycas circinalis, was described in 1994 by Ken Hill. Paleoecological studies have determined that C. micronesica has been present on the island of Guam for about 9,000 years. It is linked with Lytico-Bodig disease, a condition similar to amyotrophic lateral sclerosis (ALS), due to the neurotoxin BMAA found in its seeds, which were a traditional food source on Guam until the 1960s. The neurotoxin is present due to its symbiosis with cyanobacteria.
Macrozamia glaucophylla is a species of cycad from the genus Macrozamia and the family Zamiaceae. Endemic to New South Wales, Australia, this species has features that resembles palms, although both species are taxonomically quite different. The current population trend of Macrozamia glaucophylla is stable with 2,500 to 10,000 mature individuals. The species are found in several habitats including forest and savanna. Ecologically, Macrozamia glaucophylla lives in terrestrial system, a land-based community of organisms where the biotic and abiotic components interact in the given area.
Cycas pectinata was the fourth species of Cycas to be named; it was described in 1826 by Scottish surgeon and botanist Francis Buchanan-Hamilton from Kamrup, Assam in northeast India. The species is one of the most widespread cycads. It is found in the northeastern part of India, Nepal, Bhutan, northern Burma, southern China (Yunnan), Bangladesh, Burma, Malaysia, Cambodia, northern Thailand, Laos, and Vietnam. Cycas pectinata usually grow at elevation 300 m to 1200 m and in difficult terrains. In China, it grows in dry, open thickets in limestone mountains, red soil in sparse monsoon forests. Cycas pectinata grows up to 40 feet (12 m) tall and has very large, ovoid male cones. The tallest Cycas pectinata is a female plant in North Kamrup, Assam which measures 52.8 feet (16.1 m). The tree is the world's tallest Cycas plant. In Northeast India, the species is under severe threat due to clearing of forest and overcollection of male cones for preparation of traditional medicines. The species is listed in CITES Appendix II and IUCN Redlist.
Cycas rumphii, commonly known as queen sago or the queen sago palm, is a dioecious gymnosperm, a species of cycad in the genus Cycas native to Indonesia, New Guinea and Christmas Island. Although palm-like in appearance, it is not a palm.
Cycas thouarsii, the Madagascar cycad, is an evergreen arborescent cycad in the genus Cycas. It is named after a French botanist Louis-Marie Aubert du Petit-Thouars (1758—1831).
Cycas inermis is a vascular plant belonging to the family Cycadaceae, endemic to central and southern Vietnam. Its name in Vietnamese is Thiên tuế or Tuế lá quyết.
