The receptacle or thalamus or floral axis, in botany, is the apical enlargement of the peduncle. On the receptacle, the verticilli of the flower are inserted. It is that part of the flower, conical, flat or concave, on which the various organs of the flower are inserted; in the case of a pedunculate flower, it is the upper portion of the peduncle.
In reality it is nothing but an axis with very close internodes.
Depending on how the floral parts are inserted you can talk about:
– acyclic flower, when the flower parts are inserted following a helical (spiral) line;
– a hemicyclic flower, when some fiery parts are inserted into whorls (circle around an axis).
– a cyclic flower, when all the flowery parts are inserted by placing themselves in whorls (circle around an axis).
In general, the periante forms two whorls (set of elements of a plant such as leaves, branches or other organs, inserted on the same axis and on the same plane, which come out from a stem at the same level), the androceo forms 1 or 2 , the gyneceo 1 giving a total of 4 or verticilli. Ultimately a flower will be gloomy or penacyclic and this last will be called complete flower.