- Category: Plants
HabitatRain forest, usually in limestone areas on steep slopes or cliffs, at elevations of 150 - 770 m (490 - 2550 ft). Rainfall generally averages 2000 mm (79 in) annually, falling mainly in summer. Temperatures average 20 - 30 C (68 - 86 F) in summer, more than 20 C (68 F) in winter.
DistributionMexico, in Chiapas, Oaxaca, Tabasco, and Veracruz states, also reported from Belize and Guatemala.
Ceratozamia robusta is the largest species of the genus. As this species is now defined, it ranges from southern Mexico to Belize and Guatemala. The plants within this area are exceedingly variable as to trunk size, length and width of leaves and leaflets, size and number of spines arming the petiole and rachis, and size and shape of cones.
All Ceratozamia robusta variants originate in dense, wet, semideciduous rain forests of moderate elevation and occur most commonly on steep hillsides and cliffs. They often lean or hang from their roots, a result of the steep nature of the habitat and the loose organic soil in which they grow. Debris from the sheltering forest collects in the crowns of these plants, making them appear to have stems of large diameter. Removing this debris and old leafstalks discloses the actual size to be about half its original appearance. This forest habitat provides several conditions in which C. robusta can flourish. It protects the cycads from wind damage, provides necessary shade, and produces the moist, humus-rich soil they prefer.
In cultivation Ceratozamia robusta will form large clumps or specimens. This cycad will flourish in low-light situations if given an open, moist soil and occasional applications of fertilizer during the growing season. Because of its large size and generally very spiny stems, C. robusta must be given sufficient space to develop properly. Growth is generally good even when planted in bright or sunny areas. Closer to the coast, or in subtropical, humid environments. C. robusta can tolerate full sun, but the foliage may yellow somewhat. Generally, C. robusta has good cold tolerance and will not be damaged at a few degrees below freezing. In areas that experience frost it is best to plant it where it has some overhead protection. Its size makes it a good choice in large landscapes, especially if low-light conditions are a problem.