Leptosporangiate

Part of speech: adjective

Definitions

1. Describing a fern whose spore cases develop from a single initial cell, a feature that distinguishes it from the more primitive eusporangiate ferns
2. Relating to ferns in which each spore case grows from one cell and has a thin wall of a single layer of cells
3. Characterizing the true ferns whose sporangia arise from a single surface cell, forming a group of leptosporangiate species

Etymology: Leptosporangiate is a technical coinage, built from two Greek-derived parts that describe how ferns produce their spores. The first element, "lepto-", comes from the Greek "leptos", meaning thin, fine or slender. The second part, "sporangiate", describes organisms bearing sporangia, the small sacs in which spores develop. Put together, the term refers to ferns whose sporangia have thin walls, made of a single layer of cells, rather than the thicker walls found in the other major group of ferns. The word belongs to the scientific vocabulary of botany, where classification by fine anatomical detail became central in the 19th and 20th centuries. Because the term is a modern construction from classical roots, it was not used by the ancient Greeks, who had no concept of fern sporangia as a scientific category. The ferns it describes, however, include the great majority of living fern species, so the word names a group that makes up most of the diversity in its family.

Antonyms: eusporangiate