- Category: Plants
DescriptionA medium sized to very large cycad which in nature develops an erect or reclining trunk to 16 m tall and 40 cm diameter, although trunks are most commonly 5 - 10 m tall.
Mature LeavesNumerous in a rounded crown, graceful, arching, 1.5 - 2 m long, light green, flat in cross-section, shallowly recurved in profile, broadest near the middle and tapered to each end.
Male Cones40 - 55 x 7 - 10 cm, cylindrical, grey.
Female Cones30 - 90 x 22 - 35 cm, ovoid, grey, woolly.
Seeds4 - 5 x 3 - 3.5 cm, ovoid, the sarcotesta smooth, white to yellowish.
Distribution and HabitatOccurs in Mexico, where it was once widely distributed, but now localised in the lowlands of the Sierra Madre Oriental mountain range at altitudes of 20 - 300 m. Plants grow in shady ravines and canyons developed on limestone formations and covered with tropical evergreen forest.
NotesDioon spinulosum is one of the tallest of all cycads, with trunks reaching in excess of 15 m. Its graceful crown is reminiscent of a small palm. Its cones are among the largest of any cycad, female cones weighing in excess of 25 kg have been recorded. Being so heavy these cones commonly cause the supporting peduncle to bend and the cones slip between the lower leaves and hang below the crown. At maturity, these cones burst with a loud noise and scatter the seeds.
Dioon spinulosum is similar to both D. mejiae and D. merolae but is the tallest of the three, has strongly spinulose leaflets and graceful, arching leaves in a rounded crown. Seedlings of D. spinulosum resemble those of D. mejiae but lack prickles on the petioles.