Clematis buchananiana DC.

Vines woody. Branches shallowly 8--10-grooved, densely yellowish pubescent. Leaves pinnate; petiole 4.5--9 cm; leaflet blades broadly ovate, ovate, or elliptic, (2.5--)4--11 × (2.5--)4--10 cm, papery, undivided or 3-lobed, abaxially densely or rarely sparsely pubescent, adaxially sparsely appressed pubescent, base subcordate to rounded, margin denticulate to dentate, apex acute to acuminate; basal veins abaxially ± prominent. Cymes axillary, usually many flowered, paniclelike; peduncle 2--20 cm; bracts foliaceous or simple, ovate to lanceolate. Flowers 1.5--2.5 cm in diam. Pedicel 1--3.5 cm, densely yellowish puberulous. Sepals 4, yellow, erect, lanceolate-oblong to narrowly oblong, 2--3 × 0.5--0.9 cm, abaxially densely appressed puberulous and apically sometimes slightly emarginate, adaxially sparsely pubescent apically from middle, apex acute to rounded and often recurved. Stamens ca. 1 cm; filaments pubescent; anthers narrowly oblong to linear, 2.6--5 mm, glabrous, apex obtuse. Ovaries puberulous. Style 1.3--1.5 cm, densely villous. Achenes rhombic-elliptic, 3--5 × 2--2.5 mm, pubescent; persistent style 3.5--5 cm, plumose. Fl. Aug--Dec, fr. Feb--Mar.

Himalaya (Kashmir to NEFA), Assam, N. Burma, Indo-China, W. China.

SW Sichuan, S Xizang, Yunnan [Bhutan, India, Kashmir, N Myanmar, Nepal].

1800-3300 m

Forest margins, scrub, along streams; 1200--2800 m.

Flowering from August to December; fruiting from February to March.

Clematis buchananiana is close relative of Clematis grewiiflora, but differs from the latter in its leaflet blades abaxially densely (rarely sparsely) pubescent (vs. velutinous), cymes usually many flowered (vs. 3-flowered), sepals abaxially densely appressed puberulous (velutinous).

Clematis buchananiana is occurring in SW Sichuan, S Xizang, Yunnan of China, Bhutan, India, Kashmir, N Myanmar, Nepal.

Phylogenetic relationships within Clematis, including Naravelia, Archiclematis and Clematopsis, were analysed using nucleotide sequences of chloroplast DNA sequences matK and trnK introns, atpB-rbcL spacer, rpoB-trnC spacer, psbA-trnH-trnQ spacer, rbcL-accD spacer and the nuclear ITS regions (Miikeda et al., 2006). The phylogenetic trees resulting from these analyses suggested nine major clades. The genera Archiclematis, Naravelia and Clematopsis were found to be nested within the genus Clematis, and should be included within it. Within the genus Clematis, the traditional subgenus Viorna was found to be monophyletic. The remaining subgenera (Flammula, Clematis and Campanella) and sections Flammula, Clematis and Cheiropsis, however, were found to be paraphyletic or polyphyletic. Enormous morphological diversification and very few nucleotide substitutions within Clematis indicate the recent radiation of the genus.

Vines woody. Branches shallowly 8-10-grooved, densely yellowish pubescent. Leaves pinnate; petiole 4.5-9 cm; leaflet blades broadly ovate, ovate, or elliptic, 4-11 cm long, 4-10 cm wide, papery, undivided or 3-lobed, abaxially densely or rarely sparsely pubescent, adaxially sparsely appressed pubescent, base subcordate to rounded, margin denticulate to dentate, apex acute to acuminate; basal veins abaxially ± prominent. Cymes axillary, usually many flowered, paniclelike; peduncle 2-20 cm; bracts foliaceous or simple, ovate to lanceolate. Flowers 1.5-2.5 cm in diameter. Pedicel 1-3.5 cm, densely yellowish puberulous. Sepals 4, yellow, erect, lanceolate-oblong to narrowly oblong, 2-3 cm long, 0.5-0.9 cm wide, abaxially densely appressed puberulous and apically sometimes slightly emarginate, adaxially sparsely pubescent apically from middle, apex acute to rounded and often recurved. Stamens ca. 1 cm; filaments pubescent; anthers narrowly oblong to linear, 2.6-5 mm, glabrous, apex obtuse. Ovaries puberulous. Style 1.3-1.5 cm, densely villous. Achenes rhombic-elliptic, 3-5 mm long, 2-2.5 mm wide, pubescent; persistent style 3.5-5 cm, plumose.

Growing in forest margins, scrub, along streams; 1200-2800 m.

Clematis buchananiana là một loài thực vật có hoa trong họ Mao lương. Loài này được DC. mô tả khoa học đầu tiên năm 1817.

毛木通（学名：Clematis buchananiana）为毛茛科铁线莲属下的一个种。