Definition of "cycad"

As has been already remarked, the occurrence of genuine Cycads in the Carboniferous vegetation has not been demonstrated, and the same holds good of all the Palaeozoic floras. True Cycads, therefore, so far as known, make their first appearance in the Trias, at the commencement of the Mesozoic period, where they are represented by the genera Pterophyllum, Zamites, and Podozamites.

1872, Henry Alleyne Nicholson, A Manual of Palaeontology for the Use of Students with a General Introduction on the Principles of Palaeontology

Then, after incomputable years, he was no longer man but a man-like beast, roving in forests of giant fern and calamite, or building an uncouth nest in the boughs of mighty cycads.

1933, Clark Ashton Smith, Ubbo-Sathla

I began to count the pools, each a flare of turquoise light lost behind the high walls of the villas with their screens of cycads and bougainvillaea.

2000, JG Ballard, Super-Cannes, Fourth Estate, published 2011, page 7