As a discus in the will Botany often a disc-shaped or annular bead of the flower soil called. It forms nectar , so it is provided with nectar glands . A discus occurs, for example, with the maples ( Acer ).
The term was first used by Michel Adanson in 1764.
- Manfred A. Fischer , Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol. 3rd, improved edition. Province of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , pp. 93, 98 f.
- Gerhard Wagenitz : Dictionary of Botany. The terms in their historical context. 2nd, expanded edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2 .