Aristolochia tongbiguanensis, a new species of Aristolochiaceae from Yunnan, China

Aristolochia tongbiguanensis (Aristolochiaceae), a new species from Dehong Prefecture, Yunnan, China, is described and illustrated. It is compared with morphologically similar species including A. faviogonzalezii, A. saccata, A. balansae, A. tonkinensis and A. cathcartii. This new species differs mainly by the shape and colour of its calyx. The perianth of A. tongbiguanensis is yellowish-white with dark purple lines, the limb is nearly rectangular and covered with purple warts as well as long papillae and the throat is yellowish-white with dark purple lines and dots. Full description of A. tongbiguanensis is provided, together with line drawings, photographs and a conservation assessment for this rare vine species.