[Philadelphus gloriosus Beadle, morePhiladelphus grandiflorus Lodd. ex Schrad., Philadelphus inodorus var. carolinus S.Y.Hu, Philadelphus inodorus var. grandiflorus (Willd.) A. Gray, Philadelphus inodorus var. laxus (Schrad. ex DC.) S.Y.Hu, Philadelphus inodorus var. strigosus Beadle]
Shrub 1 - 3 m tall Leaves: short-stalked, 4 - 8 cm long, egg-shaped to oblong with a pointed tip and rounded to wedge-shaped base, few-toothed or non-toothed, shiny and hairless above, sparsely hairy along veins and in vein axils beneath. Flowers: borne solitary or in clusters of three (cymule), non-fragrant, 3.5 - 5.5 cm across, cup-shaped, with four hairless sepals, four large white petals, and many stamens. Fruit: a hardened capsule, inversely egg-shaped, four-chambered, containing many long-tailed seeds. Twigs: brown, exfoliating in second year.
Similar species: Philadelphus coronarius and Philadelphus pubescens both have fragrant flowers in clusters of five or more. Philadelphus floridus has hairy sepals and densely hairy lower leaf surfaces.
Flowering: May to June
Habitat and ecology: Introduced from the southeastern United States. In the Chicago Region, an escape was found in dry, disturbed woods along a right-of-way. In its native range, this species usually grows in the mountains along streambanks and moist hillsides or cliffs.
Occurence in the Chicago region: non-native
Etymology: Philadelphus is named after a Greek king, but also means "brotherly love." Inodorus means unscented.
Arching shrub 1-3 m; bark of young twigs brown, exfoliating the second year; lvs ovate to oblong, 4-8 cm, toothed or entire, acuminate, rounded to acute at base, glabrous, or very sparsely hairy beneath; fls in cymules of 3 or solitary, 3.5-5.5 cm wide; hypanthium, pedicels, and outer side of sep glabrous; styles separate above; seeds long-tailed; 2n=26. Streambanks and moist hillsides or cliffs, chiefly in the mts.; e. Pa., Va. and Tenn., Ga. and Ala., sometimes escaped from cult. northward. May, June. (P. grandiflorus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.