In botany, an operculum (plural opercula) is a cap-like structure in some flowering plants, mosses, and fungi.
In flowering plants, the operculum, also known as a calyptra, is the cap-like covering or "lid" of the flower or fruit that detaches at maturity. The operculum is formed by the fusion of sepals and/or petals and is usually shed as a single structure as the flower or fruit matures.
In eucalypts, (including Eucalyptus and Corymbia but not Angophora) there may be two opercula - an outer operculum formed by the fusion of the united sepals and an inner operculum formed by the fusion of the sepals. In that case, the outer operculum is shed early in the development of the bud leaving a scar around the bud. In those species that lack an outer operculum, there is no bud scar. The inner operculum is shed just before flowering, when the stamens expand and shed their pollen.
|Look up operculum in Wiktionary, the free dictionary.|
- "Glossary of Botanical Terms". Royal Botanic Garden Sydney. Retrieved 27 December 2019.
- "Learn about eucalypts". Euclid: Centre for Australian National Biodiversity Research. Retrieved 27 December 2019.
- Furness, Carol A.; Rudall, Paula J. (January 2001). "Pollen and anther characters in monocot systematics". Grana. 40 (1–2): 17–25. doi:10.1080/00173130152591840.
- Kuiper, Pieter J.C. (ed.); Bos, Marten (ed.); Soekarjo, R. (1992). Plantago: A multidisciplinary study. Berlin: Springer-Verlag. pp. 6–12. ISBN 3540536329. Retrieved 27 December 2019.CS1 maint: extra text: authors list (link)
- "The giant plants that eat mear". BBC. Retrieved 27 December 2019.
- "Form and function". Encyclopædia Britannica, Inc. Retrieved 27 December 2019.
- Reynolds, Don R.; van Brummelen, J. (1981). Ascomycete Systematics : the Luttrellian Concept (Chapter 3 - The Operculate Ascus and Allied Forms). New York: Springer-Verlag. pp. 27–31. ISBN 9781461258469.