Clematis microphylla aka Headachevine

Clematis microphylla is a climber from Australia. It belongs to the buttercup family, Ranunculaceae. People call it small-leaved clematis and headachevine. Kew gives its native range as southeast Queensland to southeast Australia. Other accounts include Tasmania. Useful Tropical Plants lists Western Australia too. It grows on riverbanks and in damp gullies. Sites range from the coast to inland tablelands. They often have sandy loam soils.

Garden sources give heights of about 10–16 feet [3–5 metres]. Useful Tropical Plants reports heights up to 33 feet [10 metres]. Sources differ on whether it keeps its leaves. PFAF says it sheds them, a trait called deciduous. Useful Tropical Plants calls it an evergreen shrub, which keeps its leaves. Its stems can trail on the ground or climb through nearby plants. Leaf stalks coil round twigs and branches to grip them. The plant thus climbs without a trunk that supports itself. Useful Tropical Plants shows white and yellow flowers. Bees and flies visit the blooms and pollinate them.

This plant likes deep, moist soil, with shade round its roots. It grows in sun or light shade in woods. Water must drain well, though the soil should stay moist. Heavy clay suits it less well if water cannot drain. The sources suggest grit to help water drain from clay. They also say it dislikes light, sandy soils. It grows on chalk, and in acid or alkaline soil. Garden records from Australia report survival at 19°F [−7°C]. PFAF warns this may not show how it fares in Britain. Cooler summers and longer, wetter winters there can make it less hardy.

People in Australia grow it as a climber for looks. PFAF also lists woodland gardens and shaded edges as sites. Growers use seed, cuttings, or layered stems to raise plants. Sow fresh seed soon after it ripens for best results. Stored seed may do better with soaking and a cold spell. Seeds can take one to nine months, or longer, to sprout. Keep young plants safe through their first winter. Plant out after the last frost you expect. This falls in late spring or early summer.

PFAF lists no known uses of this plant as food. It notes a past use as medicine to redden skin. It warns about how long skin stays in contact. Useful Tropical Plants also reports people gathering it for use in traditional medicine. Neither source reports a proven case of poisoning from this species. Both warn because its kin are poisonous. Their warnings do not rest on reports about this species. This does not mean the plant is safe to eat.