A shrub of compact habit 4 to 6 ft high, usually more in diameter; bark glabrous, peeling the second year, of a chestnut-brown colour. Leaves ovate, with a rounded base and a fine point, 11⁄2 to 4 in. long, 3⁄4 to 2 in. wide, sparsely and inconspicuously toothed, dark glossy green, with pale, appressed hairs above; paler, also glossy beneath, with only a few hairs on the veins. Flowers solitary, not scented, produced at the end of short twigs, pure white, 2 to 21⁄4 in. across, petals overlapping, making the flower square in outline, with rounded corners. Bot. Mag., t. 1478 (var. carolinus).
Native of the south-eastern USA. The date of introduction to Britain is uncertain, but plants under the name P. inodorus were in commerce in the second half of the 18th century and the true species (and also the var. carolinus, see below) were in cultivation early in the succeeding century. Miller raised a plant from seeds received from Carolina in 1738, but this died two years later.
The plant described above, which came from the Arnold Arboretum early this century, should, strictly considered, be distinguished as var. carolinus S. Y. Hu, since the species is typified by the plate in Catesby’s Natural History of the Carolinas, which shows a plant with leaves tapered at the base and flowers of cruciform shape with oblong petals. Plants which match this plate still exist in the wild and are in cultivation in the United States.
P. inodorus var. carolinus is one of the finest and most striking of the genus. It is distinguished by its glossy dark green leaves, and solitary, large, squarish flowers.
var. grandiflorus (Willd.) A.Gr. P. grandiflorus Willd.; P. speciosus Schrad. – Leaves sharply toothed, usually with tufts of hairs in the vein-axils and bristles along the main veins. As in all forms of P. inodorus the flowers are white and scentless; they are solitary or in threes, but occasionally the two lateral flowers are replaced by cymes of three or four flowers each. The flowers are cup-shaped when first expanded and occasionally (in f. quadrangulatus Hu) they have four distinct corners (a feature also of the Lemoine hybrid ‘Belle Étoile’). This variety was introduced in 1811 and has usually been known as P. grandiflorus, but some of the plants grown under that name are really P. pubescens (q.v.).
var. laxus (Schrad.) Hu P. laxus Schrad.; P. grandiflorus var. laxus (Schrad.) Torr. & Gray; P. humilis Hort. – Leaves narrower than in P. inodorus, lanceolate or elliptic-lanceolate, up to 21⁄4 in. long and 1 in. wide, tapered at the base or almost entire. A small, laxly branched shrub, native of the south-eastern USA. Introduced 1830.
P. ‘Splendens’. – A hybrid of uncertain parentage, possibly deriving from P. inodorus var. grandiflorus crossed with P. lewisii var. gordonianus. Although little known in this country, it is valued in the USA, where it originated, as it makes an excellent specimen about 8 ft high, of rounded habit, branched to the ground. The flowers are white, single, faintly fragrant, flat, with rounded petals, about 11⁄2 in. across, borne in clusters of five or sometimes more. Calyx glabrous. Leaves resembling those of the first putative parent. (Hu, Journ. Arn. Arb., Vol. 37, p. 57; Wyman, Shrubs and Vines for American Gardens (1969), pp. 326-7, with fig.)