A bushy shrub up to 10 ft high, all the vegetative parts and the peduncles and calyces warty with small black glands; young shoots slender, white-downy, longitudinally ribbed. Leaves alternate, trifoliolate, on stalks 3⁄4 to 11⁄2 in. long; leaflets lanceolate, tapered to a long acute apex, rounded or wide-cuneate at the base, entire, deep green above, paler beneath, the terminal leaflet 13⁄8 to 3 in. long, 1⁄2 to 1 in. wide, on a stalk 3⁄8 to 5⁄8 in. long, the lateral pair rather smaller and more shortly stalked. Inflorescences axillary, more or less downy, the flowers densely crowded into a spike-like raceme 1 to 2 in. long (but up to almost 5 in. long on wild plants), borne on a peduncle 11⁄2 to 31⁄2 in. long (up to 6 in. long on wild plants); calyx deeply cup-shaped about 6⁄16 in. long, unequally divided to nearly half-way into five narrowly triangular, acute, erect lobes; corolla of the usual pea-flower form, petals white, the standard blotched with blue and the keel with a blue blotch on the lower surface; stamens and style included. Legume about 1⁄4 in. long and half as wide, oblong-ellipsoid, hairy, indehiscent, enclosed in the hard dry calyx and containing a single seed. Bot. Mag., t. 990.
Native of Peru, where it was originally discovered, and of Chile; introduced, according to Aiton, around 1770. It is variable in the degree of hairiness, some Chilean specimens being more hairy than the cultivated plants and others almost glabrous, while a Peruvian specimen has the stems, petioles, inflorescence axes, and calyces densely white villose.
Probably all the plants now cultivated in Britain derive from Harold Comber’s introduction from Chile in 1926 (C.572). In his field-note he adds: ‘much grown in Chile for the preparation of a refreshing drink made by whisking water with the young shoots and adding sugar. This is very good.’ It is known there by the Indian name ‘culén’. This form should be almost hardy in a sunny sheltered place. At Kew a plant has grown for many years outside the southern end of the Temperate House and flowers freely in summer.