What Fern Is Like a Cycad?

Physical Similarities

• Possessed of pinnate leaves with multiple leaflets, ferns and cycads are sometimes mistaken for each other. Based on leaf shape, some cycads are also easily confused visually with palm plants and trees. All three divisions of plants are characterized by pinnate leaves arranged on flexible stems, or fronds, issuing from a center point or trunk, most often forming a single cluster of leaves. While palm trees develop a variety of shapes and sizes, ferns and cycads both tend more to resemble the primitive silhouettes recorded in fossils.

Habitat Similarities

• Ferns and cycads further share a preference for tropical or subtropical climates, often growing as understory plants in forests in USDA hardiness zones 9 to 11. According to the Royal Botanical Gardens and Trust of Australia, different cycad genera can be found in Australia, New Zealand, Africa, South and Central America, Asia and the most southern regions of North America. The Garden's interactive Cycad map indicates that most cycad genera are specific to a country or region: Ceratozmia, Zamia and Dioon cyclads growing in Mexico and Central America; Encephalartos in Africa; and members of the Cycas genus in Asia. While tolerance for sun may vary, poor tolerance for temperatures near or at freezing is common to all genera. Many tree ferns also prefer tropical or subtropical conditions, although some varieties display more cool-weather tolerance. Both Dicksonia and some Cyathera species grow well in the mild zones 6 to 8a of the Pacific Northwest. Shade tolerance plays a bigger part in successful growth than the need for heat. All tree ferns, however, share low tolerance for temperatures near or at freezing and, even with mulching and protection, may show considerable damage if touched by frost.

Propagation Differences

• While visually similar, ferns and cycads are unrelated to each other and differ completely in methods of reproduction and propagation. Plants in the fern, Pteridophyta, division or phylum reproduce by means of spores on the backs of their leaves. Cycads, in the Cycadophyta division, have much more in common botanically with evergreen trees than with ferns. Cycads produce cones, either at the center of the leaf cluster or at branch axes. New plants sprout from seeds contained in the cone or cones.

Ferns that Resemble Cycads

• Since resemblance is by habitat but even more so by appearance, the closest visual fern relatives to cycads are the tree fern families Blechnum, Cibotium, Cyathea and Dicksonia. All contain varieties of ferns resembling cycads in their stout single trunks and single cluster of fronds emanating from the top of the trunk. Some varieties are best known in New Zealand and Australia, where they are grown in the company of cycads. The National Tropical Botanical Gardens of Hawaii contain both tree ferns and cycads. In climates where winter temperatures go below freezing, even occasionally, these primitive-looking ferns require frost protection, as do visually-similar cycads.