Aristolochia involuta X.X.Zhu, Z.X.Ma & J.S.Ma, 2017

Zhu, Xin-Xin, Liao, Shuai, Ma, Zheng-Xu, Xu, Bo, Wang, Zhang-Hua, Wang, Yuan & Ma, Jin- Shuang, 2017, The taxonomic revision of Asian Aristolochia (Aristolochiaceae) III: Two new taxa of Aristolochia and morphological revision for the flower character of A. obliqua from Yunnan, China, Phytotaxa 332 (3), pp. 269-279 : 269-271

Aristolochia involuta X.X.Zhu, Z.X.Ma & J.S.Ma , sp. nov. ( Figs. 1 , 2 A–H & 3 )

The new species is similar to A. bambusifolia C.F.Liang ex H.Q. Wen (1992: 217) in the saccate and involute calyx limb, but differs in its lamina oblanceolate to oblong, veins 5–8 pairs, base cuneate to broadly cuneate (vs. lamina linear-lanceolate, veins 12–16 pairs, base rounded or shallowly cordate in A. bambusifolia ), upper tube inverted triangle and flattened (vs. cylindric, gradually dilated in A. bambusifolia ). Detailed morphological comparison is shown in Table 1 and Fig. 2 .

Type:— CHINA. Yunnan: Malipo County, Mt. Hua , 23°02’16”N, 104°43’38”E, 983 m, 7 February 2017, X.X.Zhu ZXX17003 (holotype CSH-0137427!; isotypes CSH!, IBSC!, KUN!, PE!) .

Climbing shrub. Stem terete, densely villous when young, old branch glabrescent. Petiole 1–2 cm long, densely villous; lamina oblanceolate to oblong, 9–18 × 3–7 cm, adaxially glabrous or villous along midrib, abaxially villous, veins 5–8 pairs, base cuneate to broadly cuneate, apex acuminate. Cyme on old woody stems, 1–2-flowered. Bractlet ca. 1 mm long, densely villous. Calyx yellowish white with dark purple veins; tube geniculately curved, abaxially villous; basal tube 4–5 cm long, inside red at base, yellowish white with red stripes above base, upper tube inverted triangle and flattened, inside yellowish white at base, dark purple above base; limb saccate and involute, 3.5–4 cm wide; adaxially dark purple. Anthers 6, oblong, 3–4 mm long, adnate in 3 pairs to the base of gynostemium, opposite to the lobes. Gynostemium ca. 7 mm long, 3-lobed, lobes bilobate, margin crispate. Ovary terete, ca. 1.5 cm long, densely brown villous. Capsule cylindric, 8–10 × 2.5–3 cm. Seeds ovate, 6–6.5 × 4–5 mm.

Distribution and habitat: —The new species is currently known to Malipo County, Yunnan, China, at elevations between 980 m and 1000 m. It is locally rare and grows in the forests together with Ananas comosus (L.) Merr. ( Bromeliaceae ), Castanopsis sp. ( Fagaceae ), Macaranga sp. ( Euphorbiaceae ), Phyllostachys sp. ( Poaceae ), Saurauia sp. ( Actinidiaceae ), Schisandra sp. ( Schisandraceae ), Smilax sp. ( Smilacaceae ), Tetrastigma planicaule (Hook.f.) Gagnep. ( Vitaceae ), etc.

Phenology: —Flowering specimens were collected in February. Fruiting specimens were collected in May.

Etymology: —The specific epithet derives from the involute calyx limb of the new species. The Chinese name is given as “ffiḭĥẘṻ”.

Additional specimen of A. involuta examined (paratype): — CHINA. Yunnan: Malipo County, 9 May 2017, X.X.Zhu ZXX17063 (CSH).

Specimens of A. bambusifolia examined: — CHINA. Guangxi: Huanjiang County, 19 April 2012, W. B.Xu et al. ML1114 ( IBK) ; Longlin County, 11 April 1991, H. Q.Wen 00459 (types IBK, PE) . Yunnan: Guangnan County, 24 March 1940, C. W.Wang 88101 ( KUN) .

Figures

FIGURE 1. Aristolochia involuta. A. Branch, B. Inflorescence, C. Longitudinal-section of flower (showing inside structure), D. Flower in frontal view, E. Anthers and gynostemium, F. Capsule. (Drawn by H.X.Dong, A–E from X.X.Zhu ZXX17003, F from X.X.Zhu ZXX17063.)

FIGURE 2. A–H: Aristolochia involuta. A. Habit, B. Leaf, C–D. Flower, E. Longitudinal-section of flower (showing inside structure), F. Anthers and gynostemium, G. Capsule, H. Seed. I–J: A. bambusifolia. I. Habit, J. Flower. (A–H: photographed by X.X.Zhu; I–J: photographed by Y.Liu.)

FIGURE 3. Holotype of Aristolochia involuta (CSH-0137427).