Heartleaf Mock Orange

Philadelphus cordifolius I^ange, Fort. Landboh. Fril. 66. 1871
Bot. Tidsskr. III. 2: 132. 1878.
A rather tall shrub, 2 m. or more high, with ascending or spreading branches ; bark of the young twigs cinnamon-brown, glabrous, shining, of the previous season's growth darker brown and exfoliating, and of the older stems light-gray ; buds enclosed in the bases of the petioles ; petioles 1-1.5 cm, long ; leaf-blades usually broadly ovate, shortacuminate or acute at the apex, rounded at the base, sometimes rounded-ovate or subcordate or those subtending, the flower clusters lance-ovate, mucronate-denticulate, glabrous or pubescent in the axils of the veins beneath, dark-green above, paler beneath, 5-10 cm. long, 5-7-ribbed ; flowering branches 1-4 dm. long, with 2-5 pairs of leaves and a rather dense panicle of 1540 flowers, the lower branches of the inflorescence often subtended by leaves ; hypanthium glabrous ; sepals lance-ovate, acute or rarely short-acuminate, about 5 mm. long, glabrous without, silky-tomentulose within; petals oval, usually emarginate, 10-12 mm. long; stamens numerous ; styles united to the apex ; stigmas clavate, smaller than the anthers ; capsule obovoid, 7-8 mm. long.
Type locality : Described from cultivated specimens from California. Distribution : California, on the western slope of the Sierra Nevada.