Contemporary Circumscription Compared with A Utah Flora 4th ed.

Bio430

Cycadaceae

Not in A Utah Flora; this family is not found natively in Utah. Historically some authors have  recognized all cycads in this family while others have recognized 3 or 4 families.  Today, three families are generally recognized in Cycadophyta. Cycas revoluta has the common name Sego Palm and may be used in landscaping  in warmer places.

Key Features

Cycads are tree-like, with a single unbranching stem that may be mostly underground in some species or quite tall (rare branching sometimes occurs).  Leaves are the largest among gymnosperms, pinnate compound, and leathery.  Reproduction is dioecious, with microsporophylls always aggregated in cones, but ovules are attached to ovuliferous (ovule bearing) leaves instead of cones. The genus Cycas is the only genus in  the family, and the only genus of ‘cycads’ that does not form female cones. Cycad sperm have flagella, a hold-over showing their relationship to more primitive plants.  Cycads were once abundant on earth, but now have somewhat restricted distributions.