a thickened, raised mass of hardened
- (in Poaceae) a hard projection at the base of the floret or spikelet the sharp point of the seed;
- (in Orchidaceae) the raised structures, often consisting of ridges,
papillae or projections, occurring on the upper surface of the
Copyright: Mike Bingham, Annette Willemen, Bart Wursten, Petra Ballings and Mark Hyde, 2011-17
Bingham, M.G., Willemen, A., Wursten, B.T., Ballings, P. and Hyde, M.A.
. Flora of Zambia: Glossary details: callus.
http://www.zambiaflora.com/speciesdata/glossary-display.php?glossary_id=95, retrieved 26 March 2017