Dioon
(from dis, two, and oon, an egg; in reference to each scale bearing two ovules; otherwise from the seeds being borne in twos). SYN. Platyzamia. ORD. Cycadaceae. A very singular genus containing a couple of species, both natives of Mexico. They make noble objects in a collection of ornamental-leaved plants. Dioons thrive best in a compost of good loam and river sand, and succeed well in an ordinary greenhouse, except when in a growing state, at which period they should have the warmth of a stove. Propagated by seed, which are very large. Miquel observes that this genus is more closely allied to certain fossil Cycadaceae than is any other living representative of the order.
D. edule (edible).* l. glaucous-green, pinnate, from 3ft. to 6ft. in length, and 6in. to 7in. in breadth, tapering towards the base, where they are clothed with short white woolly hairs; texture very firm. Stems about 3ft. in circumference. h. 3ft. 1844. (B. M. 6184.) The fruit of this plant is as large as a chestnut, and is powdered by the natives, and formed into a kind of arrowroot.