"Dioon spinulosum " prefers well-drained soil with regular water.
2.
"Parallocorynus " has to date only been collected from the cycad genus " Dioon ".
3.
It was revised in 1997, with one variety being elevated to species status as " Dioon sonorense ".
4.
The genus name " Dioon " means " two-egged ", referring to the two ovules ( see photo below ).
5.
Death rates among seedlings are considerable, which is detrimental to a slow-growing plant such as the " Dioon edule ".
6.
Dioons are dioecious, D . tomasellii ", which are smaller overall, with shorter trunks, much shorter fronds, and smaller cones.
7.
"Dioon spinulosum " has pinnate leaves that grow to about 5-7 ft ( 1.5-2.1 m ) in length and radiate out from the trunk.
8.
Similarly " Rhopalotria " is associated with various species of " Zamia " cycads, though one of the as yet undescribed species was collected from " Dioon spinulosum ".
9.
In 1997 the collection was further improved by the acquisition of a variety of worthy specimens, including " Dioon spinulosum, Encephalartos altensteinii, Encephalartos longifolius, Encephalartos villosus, Macrozamia moorei " and " Zamia furfuracea ".
10.
Its plantings include Liliaceae ( agave, cordyline, dasylirion, dracaena, yucca ), and cactus and cycads ( Cycas, Dioon, Encephalartos ), as well as " Cocculus laurifolius ", euonymus, oleander, etc.