Sphenophyllum

noun

Sphe·​no·​phyl·​lum

ˌsfēnəˈfiləm

: a genus of Paleozoic fossil plants that are related to the club mosses and horsetails but are usually placed in the separate order Sphenophyllales, that have jointed stems, cuneate leaves in whorls of three or multiples of three, and terminal cones or sporophylls, and that occur from the Devonian to the Permian

Word History

Etymology

New Latin, from sphen- + -phyllum

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!