Clematis heracleifolia DC.

A semi-shrubby, deciduous plant, growing 2 to 3 ft high; stems ribbed, more or less downy, brownish red. Leaves composed of three leaflets, the terminal one much the largest, roundish ovate; shallowly, unequally, and sparsely bristly toothed; the base slightly heart-shaped, or almost cut off straight; from 2 to 5 in. long and wide; the side leaflets are similar in texture, etc., but are only half the size, and are scarcely stalked. Flowers 3⁄4 to 1 in. long, produced from the joints of the stems of the year in dense short clusters, each flower on a downy stalk 1 in. or less in length. They are tubular at the lower half and swollen at the base, the four sepals curling outwards and backwards towards the end, deep blue outside, downy. The flowers are unisexual, but both sexes appear on one plant. Seed-vessels with feathered tails.

Native of Central and N. China; introduced in 1837; flowering from July to September. It is one of a group known as Tubulosae, whose four sepals close up and form a half-tubular flower of the same shape as hyacinths; to this group C. stans as well as other minor species belong. They are notable for the large leaves and robust, although semi-herbaceous growths.

From the Supplement (Vol. V)

Near to the var. davidiana, and an improvement on the form usually cultivated, is ‘Wyevale’, raised by Mr Williamson at the Wyevale Nurseries. The flowers are fragrant, as indeed they are in var. davidiana, though less markedly so. This received an Award of Merit in 1962, when exhibited by Mr Williamson.

The clonal name ‘Manchu’ has been given to a good form of the var. davidiana, with deep blue flowers. It was raised by Raymond Evison from seeds collected by Roy Lancaster near the Great Wall of China in 1980 (L.437). See further in The Garden (Journ. R.H.S.), Vol. 109, p. 247 (1984).