''Dioon spinulosum'', giant dioon, or gum palm, is a

cycad Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...

endemic to limestone cliffs and rocky hillsides in the

tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...

s of

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

and

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. It is one of the tallest cycads in the world, growing to 12m in height. The tree is found at low elevations to 300 m above sea level. ''Dioon spinulosum'' prefers well-drained soil with regular water. It will grow in soils containing few nutrients, in soils rich in limestone, and on slopes. It is hardy to USDA Zones 9B – 11. ''Dioon spinulosum'' has

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

leaves that grow to about 5–7 ft (1.5-2.1 m) in length and radiate out from the trunk. The 120-240 leaflets on each leaf are small and flat, have small thorns and taper to a sharp point.

References

External links

*Encyclopædia Britannic
Giant dioon
*Michigan State University Horticultur

Dioon, spinulosum Data deficient plants {{cycad-stub