|Leaves and male cone of Cycas revoluta|
The genus is native to the Old World, with most species around the equatorial regions. It is native to eastern and southeastern Asia including the Philippines with 6 species (4 of which are endemic), eastern Africa (including Madagascar), northern Australia, Polynesia, and Micronesia. Australia has 26 species, while the Indo-Chinese area has about 30. The northernmost species (C. revoluta) is found at 31°N in southern Japan. The southernmost (C. megacarpa) is found at 26°S in southeast Queensland, Australia.
The plants have often been considered to be a living fossil. The earliest fossils of the genus Cycas appear in the Cainozoic, but Cycas-like fossils occur well into the Mesozoic. Cycas is not closely related to other genera of cycads. Phylogenetic studies have shown that Cycadaceae is the sister-group to all other extant cycads.
Other websites[change | change source]
- Cycad Pages: Cycas
- Singh R. & Radha P. 2006. Cycas annaikalensis, a new species of Cycas from the Malabar Coast, Western Ghats, India. Brittonia 58 (2): 119-123.