plural noun

: a subdivision of Tracheophyta comprising vascular plants with no roots, leaves only partially differentiated or lacking, no leaf traces, a usually protostelic vascular cylinder, and the sporangia merely terminal enlargements of the stem compare lycopsida , pteropsida , sphenopsida

Word History


New Latin, from psil- + -opsida (as in lycopsida)

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Dictionary Entries Near Psilopsida

Cite this Entry

“Psilopsida.” Dictionary, Merriam-Webster, Accessed 15 Jul. 2024.

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