(Bruehl) Tamura
Description
Clematis tongluensis is a Himalayan climber recorded from Nepal, Bhutan, India, China and Myanmar, with additional cultivated or vouchered material noted from Canada; GBIF holds around 58 occurrences. It is a plant of temperate to subalpine forest, scrambling through shrubberies, over forest-edge thickets and along open slopes, generally between about 2700 and 3700 m. It was photographed at Tsochenchen in Bhutan at 3550 m in June, where it climbs through rhododendron and conifer woodland margins, flowering at the onset of the summer monsoon.
The species is a woody to semi-woody climber with ribbed, somewhat pubescent stems that twine and clamber by means of the petioles. The leaves are ternate to pinnate, the leaflets ovate to lanceolate, acuminate and serrate, often thinly hairy. The flowers, borne singly or in few-flowered cymes, are nodding and broadly campanulate, lacking true petals; the four (rarely more) thick, spreading to recurved sepals are usually creamy-white to pale yellow, sometimes flushed purplish, with tomentose margins. Numerous stamens surround the carpels, and the fruit is a head of achenes each bearing a long, plumose persistent style.
Clematis tongluensis sits within the bell-flowered Sino-Himalayan groups of the genus, allied to the Montanae and related sections, and has at times been treated under or confused with the variable C. montana complex. Its nodding campanulate flowers and montane forest habitat are diagnostic. The species is fairly widely distributed and faces no recognised conservation threat, though it depends on the persistence of intact temperate broad-leaved and coniferous forest.
Author: (Bruehl) Tamura · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, A Revision of the Genus Clematis (Grey-Wilson), Annotated Checklist of the Flowering Plants of Nepal