Subspecies, varieties, forms and cultivars of plants belonging to the Cycas rumphii complex

The C. rumphii complex comprises a number of related taxa which have sometimes been considered conspecific. Differences between these taxa lie mainly in the shape and indentation of the lamina of the megasporophylls.

• Cycas circinalis L.: has leaflets not more than 13 mm broad, non-pepectinate megasporophyll with large lamina. Microsporophyll apex attenuate, reflexed. Distribution: southern India.
• Cycas glauca Miq.
• Cycas micronesica K.D.Hill
• Cycas rumphii Miq.: has broad, falcate, hard, glossy leaflets with relatively broad bases, usually wholly spinescent petiole, and narrowly triangular megasporophyll lamina with a slender apical spine. Distribution: Indonesia, S. Borneo ans along the north coast of Papua New Guinea.
• Cycas thouarsii R.Br.: has distinctly bluish new leaves with wholly spinescent petioles and the pronounced stout spines on the microsporophylls. Seeds do not have a crested sclerotests. Distribution: Madagascar, the Comoros Islands, Mayotte and the Seychelles. Scattered occurrences are also known on the East Coast of Africa from Tanzania throughout Kenya south the Mozambique.
• Cycas zeylanica (J.Schust.) A.Lindstr. & K.D.Hill