Clematis heracleifolia, the tube clematis (大叶铁线莲 da ye tie xian lian), is a species of flowering plant in the buttercup family Ranunculaceae, native to central and northern China. Unlike most other members of the genus Clematis, it has a scrambling rather than a climbing habit.Growing to 1 m (3.3 ft) tall by up to 50 cm (20 in) broad, it is a deciduous sub-shrub with broad downy leaves in groups of three, and delicate clusters of elongated tubular blue flowers in late spring and summer. Mature blooms ...