The difference in flower shape arrived at through selection and breeding is well illustrated by comparing Hydrangea paniculata and the cultivar Hydrangea paniculata ‘Tardiva’ where the panicles can exceed 250mm in length.
Both the species, seed of which was collected in Japan, and the large flowered Tardiva can be seen growing in the Garden. Logan Botanic Garden also grows several of this species’ other named cultivars.
In Hydrangea paniculata ‘Tardiva’ the terminal panicles of separate male and female flowers are shaped to resemble ice cream in a cone. Those of the species are similarly borne at the end of the current year’s growth but have no shape of merit. The leaf shape, with denoted serrate edge and red petiole colour are prominent in the species, but these characters less obvious in the cultivar.
The terminal panicles are composed of two types of flower; the showy ray floret of 4 or 5 flat petals which are sterile and the smaller round buds opening to reveal flower parts, both male and female. Colour change is from light green on development through showy white to pink on fading. The whole exudes a musty, not unpleasant scent.