A deciduous climbing shrub growing 12 ft or more high; young shoots very slender, glabrous, hollow, exuding milky juice when cut. Leaves opposite, heart-shaped, tapering at the apex to a long fine point, toothless, 2 to 31⁄2 in. long, 11⁄4 to 2 in. wide, dark dull green and glabrous above, paler beneath, with tufts of white down in the axils of the veins; stalk 1⁄2 to 2 in. long. Flowers sweetly scented, produced six to eight together in corymbs from the leaf-axils, from June to September. Corolla white or creamy white, funnel-shaped, 2 in. long, 11⁄2 in. wide, five-lobed, the lobes roundish ovate, spreading, overlapping; glabrous outside, hairy inside the tube. Anthers five, yellow, scarcely stalked, 3⁄8 in. long, crowded together in a column towards the base of the tube and concealing the stigma. Calyx green, with five awl-shaped lobes 3⁄8 in. long. Seed-pods (follicles) usually in pairs, each from 12 to 16 in. long, slenderly cylindrical, 1⁄4 in. wide. Seeds bearded. Bot. Mag., t. 3797.
Native of the Argentine; introduced in 1837 by H. J. Mandeville, at that time British Minister at Buenos Ayres, and in compliment to whom the genus was named. Usually grown in greenhouses, where it is valued for the abundant, sweetly scented blossoms, it can, in the milder parts of the country, be grown on a sunny wall, planted in well-drained, light, loamy or peaty soil. It has succeeded well and borne its remarkable seed-pods in the Vicarage Garden at Bitton in Gloucestershire, and at Leonardslee in Sussex. In Cornwall it is even more luxuriant. It is sometimes known as “Chilean jasmine”.
M. laxa (Ruiz & Pavon) Woodson Echites laxa Ruiz & Pavon – This species, described from Peru, resembles M. suaveolens in many respects and is mentioned here because M. laxa would be the correct name for the species if the two were united, as they have been by Dr Woodson. But the differences between them are substantial and it seems preferable to retain the name M. suaveolens for the plant of Argentina, at least for the time being.