Exochorda Racemosa or Pearl Bush
The generic name, derived from the Greek words exo, meaning outer, and chorda, meaning keel, refers to the keel-shaped fruit. The genus has only four species found in China, Manchuria, Korea and Asia Minor. The shrubs grow to a height of 5 m (16 ft). The leaves are obovate or elliptical and the strikingare snow white and borne in terminal racemes. The calyx is broad and shallow, the corolla in five parts with broadly ovate, shell-shaped petals. Striking also are the fruits — five-valved, five-sided, broadly keeled capsules.
The pearl bush is an early-flowering shrub, the blossoms appearing as early as late April. It is propagated by means of seeds which are sown immediately after they are harvested. If they cannot be sown right away and dry up they should be stored for the winter at a temperature of about 10° C (50° F), stratified in spring and sown in the autumn. The pearl bush needs a moderately heavy, loamy, garden; if the soil is lighter it must not become dry. It thrives in sun as well as partial shade. The shrub is lovely when in flower and attractive during the fruiting period. It is most effective grown as a solitary specimen, though its size makes it better suited for parks than for gardens, particularly small ones.
Also frequently grown is the species Exochorda giraldii, with smaller flowers, and the large-flowered variety E. giraldii wilsonii,which blooms at the beginning of April.