inflorescence
The flowers of Sorbus aria, whitebeam, form a corymb in which all the lateral branches are of different lengths, with the lowermost of greater length so that all the flowers are brought to the same level. The flowers of Bubomus umbellastus, the water gladiolus, form an umbel (B) where all flower stalks arise from the same point. The inflorescence of Astrantia major, the masterwort, is a compound umbel (C) in which the lateral branches are themselves subdivided.
The flowers of Sorbus aria, whitebeam, form a corymb in which all the lateral branches are of different lengths, with the lowermost of greater length so that all the flowers are brought to the same level. The flowers of Bubomus umbellastus, the water gladiolus, form an umbel (B) where all flower stalks arise from the same point. The inflorescence of Astrantia major, the masterwort, is a compound umbel (C) in which the lateral branches are themselves subdivided.
An inflorescence is the conspicuous cluster of flowers that is produced by many angiosperms. There are several types of inflorescence, the forms of which vary according to the arrangement of individual flowers. In the type of inflorescence known as a raceme the flowers are attached to the main flower axis by short stalks, or pedicels, of equal length, for example the hyacinth, while in the spike there are no pedicels and the flowers are directly attached to the main axis, for example the gladiolus.
Plants such as lilac and oats have an inflorescence similar to a raceme, but the pedicels bear more than one flower. This formation is called a panicle.
In the corymb, the pedicels are of unequal length so that the inflorescence has a flat-topped appearance, for example hawthorn. In some plants, particularly those of the family Compositae, all the flowers are bunched on a flat disk, this arrangement being known as a head.
In the simple umbel the pedicels appear to arise from a central point, while in the compound umbel several simple umbels are borne on a single stalk or ray and each inflorescence comprises a number of rays growing from the tip of the main axis. A simple umbel is produced by the milkweed and most members of the carrot family (Umbelliferae) produce compound umbels.
