An evergreen shrub of lax, graceful habit, to 6 ft high. Leaves ovate, cordate at the base, 2 to 4 in. long, slender-pointed, coarsely toothed. Flowers pendulous, borne singly in the leaf-axils from April onwards; calyx inflated, rich red, about 1 in. long; corolla yellow, about 1⁄2 in. longer than the calyx. The stamens and stigmas form a club-shaped stalked cluster that stands out well beyond the corolla. Bot. Mag., t. 5717.
Native of Brazil. Although by no means hardy, it will survive most winters on a warm, sheltered wall, and is certainly one of the most attractive subjects for such a situation. There is also a variegated form in which the leaves are prettily blotched and tessellated with bright yellow. Its hybrids with A. pictum are known as A. × milleri, of which several have been raised, with yellow flowers streaked with red; the leaves are longer than in A. megapotamicum and relatively narrower.
Although A. megapotamicum has no part in their make-up, certain other tender hybrids may be mentioned here which are sometimes grown out-of-doors in the milder parts. The main parents of this group are thought to be A. darwinii (leaves about twice as long as wide, velvety) and A. striatum (leaves almost as wide as long, glabrous), both with orange flowers, veined with red. Three of the best known in this miscellany are 'Golden Fleece', with rich yellow flowers; 'Ashford Red', with large flowers of a colour described as 'a deep shade of crushed strawberry'; and 'Boule de Neige', perhaps a hybrid of A. insigne, with white flowers; according to Thurston, it once reached a height of 13 ft in Cornwall.