Philadelphus, a genus of shrubs popularly called mock orange, and sometimes syringa, a name the use of which should be discouraged, as it properly belongs to the lilac. The genus is now placed in the saxifrage family, and comprises shrubs with opposite leaves without stipules; their abundant white flowers, sometimes solitary, are usually in corymbs; the calyx having its tube coherent with the ovary, with four or five valvate lobes; petals four or five; stamens 20 to 40; styles three to five, the ovary with the same number of cells, becoming when ripe a pod which splits into as many pieces as there are cells. There are several species, natives of the southern Atlantic and Pacific states and of Japan, and these have varied much by cultivation; our native species are scentless or nearly so. P. inodorus has mostly entire ovate-oblong leaves, and small flowers; P. grandiflorus is a much taller shrub, with long and recurving branches, usually toothed leaves, and very large flowers; both are found from Virginia southward; P. hir-sutus of North Carolina and Tennessee has small acute hairy leaves, and the small flowers solitary or two or three together; P. Gordonianus of Oregon so much resembles P. grandiflorus that it is suspected of being a variety of it; P. Galifornicus and P. Lewisii are also found on the Pacific coast; some of these, especially P. grandiflorus and P. Gordonianus, are cultivated for the abundance and beauty of their large pure white flowers, but neither is so common as P. coronarius, sometimes called the garland mock orange, which has been long in cultivation, and the native country of which is not well known; some refer it to Japan, and others consider it a native of southern Europe. It has erect branches, oblong-ovate leaves, which have exactly the odor and taste of cucumbers, and large clusters of cream-white flowers, which are exceedingly fragrant; there is a dwarf variety, and one with double flowers.
These shrubs form such dense clumps that they require no special propagation other than to dig up an old stool and pull it apart.
Gordon's Mock Orange (Philadelphus Gordonianus).