Aristolochia austroyunnanensis S.M. Hwang (1981: 228)

Zhu, Xin-Xin, Liao, Shuai, Sun, Zeng-Peng, Zhen, Ai-Guo & Ma, Jin-Shuang, 2017, The taxonomic revision of Asian Aristolochia (Aristolochiaceae) II: Identities of Aristolochia austroyunnanensis and A. dabieshanensis, and A. hyperxantha-a new species from Zhejiang, China, Phytotaxa 313 (1), pp. 61-76 : 62-64

Aristolochia austroyunnanensis S.M. Hwang (1981: 228) ( Figures 1 & 2 A–C )

Lectotype (designated here):— CHINA. Yunnan: Pingbian County, Waga , 1800 m, 14 June 1956, Sino-Russ. Exped. 2075 (PEM-0001663!, isolectotype IBSC-0127607!).

Perennial climbing liana. Petiole 2–4 cm long, villous; lamina narrowly ovate, ovate-lanceolate or ovate-elliptic, 12– 20 × 5–8 cm, leathery, adaxially slightly villous along veins, abaxially densely villous, base shallowly cordate, apex acuminate, veins pinnate. Cymes on old woody stems, 1- or 2-flowered. Pedicel pendulous, 2–4 cm long, yellowbrown villous; bractlets ovate-lanceolate, adaxially almost glabrous, abaxially densely villous. Calyx tube geniculately curved, outside densely villous, inside densely villous at basal portion, glabrous at upper portion; utricle is indistinct with the tube; basal portion of tube cylindric, 5–6.5 cm long, inside dark-purple at base and pale-yellow with purple stripes above base, upper portion of tube cylindric, ca. 3 cm long, inside yellow; limb suborbicular, flat, 6–8 × 4–7 cm, inner surface dark-purple with light-yellow stripes; throat yellow, 1.5 cm in diam. Anthers 6, oblong, adnate in 3 pairs to the base of gynostemium, opposite to the lobes. Gynostemium ca. 6 mm long, 3-lobed, apex of lobes obtuse. Ovary terete, ca. 1.5 cm long, densely rusty villous. Capsule narrowly ellipsoidal, 10–15 cm long, dehiscing basipetally. Seeds triangular-ovate, 7–8 × 5–6 mm.

Distribution and habitat: — Aristolochia austroyunnanensis is currently known to Guangxi (Napo County) and Yunnan (Maguan County, Pingbian County, Xichou County, and Yuanyang County), China. It grows on the limestone mountain slope, in dense forest at elevations between 1600 m and 2100 m.

Phenology: ―Flowering was recorded in May (J.Cai et al. 14CS9201 (KUN)) or September ( Hwang 1988); fruiting was recorded in June (Sino-Russ. Exped. 2075 (IBSC & PEM)).

Note: ― Aristolochia austroyunnanensis was published by Hwang (1981), who thought it was morphologically similar to A. petelotii O.C. Schmidt (1933: 95) but it can be distinguished from the later by its ovate-oblong or ovate-elliptic leathery leaf, lamina with shallowly cordate base and acuminate apex, as well as smaller limb. Aristolochia austroyunnanensis was later recognized both by Wu (1984) and Hwang (1988). After examining the type specimens of A. petelotii in P (P-02028702 & P-02028703), Ma (1989a) thought that there was no essential difference between these two species. Thus, Ma (1989a, 1989b) regarded A. petelotii as a new record to China and reduced A. austroyunnanensis as its synonym. The treatment of Ma (1989a, 1989b) was later adopted by Tao (1997) and Hwang et al. (2003).

Based on re-examination of the protologue, specimens, and live plant photos of these two species, we find that Aristolochia austroyunnanensis differs from A. petelotii by its leathery leaf (vs. herbaceous or membranous), flat dark-purple limb with light-yellow stripes (vs. bursiform dark-purple limb with white stripes) and yellow throat (vs. milk-white mixed with black). Detailed morphological comparison between these two species is shown in Table 1 and Figure 2 .

Aristolochia austroyunnanensis is also similar to A. fangchi Y.C.Wu ex L.D.Chow & S.M.Hwang in Hwang et al. (2003: 264) in the shape of flower and calyx limb, but it differs from the latter in the shape of leaf base and the inner surface color of calyx tube, which are also compared in Table 1 and Figure 2 .

The holotype of A. austroyunnanensis was stated to be deposited in KUN by Hwang (1981). However, it was confirmed that the holotype had been lost and no duplicates could be found (Jing-hua Wang, a custodian of KUN, pers. comm.). Given this and based on Art. 9.11 and 9.12 of ICN ( McNeill et al. 2012), the paratype conserved in PEM, which bears more characters than its duplicate in IBSC, is chosen here as the lectotype.

Specimens of A. austroyunnanensis examined: — CHINA. Guangxi: Napo County, 23 February 1976, D.Fang & D.Y.Liu 22129 ( GXMI) . Yunnan: Pingbian County, 5 May 1954, P.Y.Mao 04144 ( PEM), 25 May 2014, J.Cai et al. 14CS9201 ( KUN) ; Yuanyang County, 7 June 1974, Lüchun Exped. 1604 ( KUN) .

Specimens of A. petelotii examined: — CHINA. Yunnan: Lüchun County, 27 October 1995, S.K.Wu et al. 2510 ( KUN) ; Malipo County, 7 August 2015, X.X. Zhu & S. Liao ZH112 ( CSH), 30 March 2017, X.X. Zhu ZXX17016 ( CSH, XYTC), 8 May 2017, L.Wu & Z.J.Wen 5840 ( CSFI) .— VIETNAM. Hanoi: 4 March 2014, J.S.Ma & M. Deng DM6763 ( CSH) . Tonkin: September 1932, A.Pételot 4418 (syntypes P-02028702! & P-02028703!) .

Specimens of A. fangchi examined: — CHINA. Guangdong: Boluo County, s.a. (sine anno), Anonymous 184 ( IBSC) ; Dinghu District , 16 April 1963, G.Q.Ding & G.L.Shi 324 ( IBSC, NAS), 3 August 1963, G.Q.Ding & G.L.Shi 823 ( HITBC, IBSC), 14 April 1966, G.L.Shi & K.M.Zhang 2719 ( IBSC), 12 August 1981, G.L.Shi 14014 ( IBSC), 16 March 2015, X.X.Zhu & Z.X.Hua ZH008 ( CSH) ; Fengkai County, 3 June 1974, Yue-74 Exped. 5028 ( IBSC) ; Gaoyao City , 28 June 1956, F.D. Chou 0149 ( IBSC), 29 June 1956, L.D.Chou 0149 ( PEM), 23 December 1956, C.Huang 162644 ( IBSC) ; Lianshan County, October 2002, H.G.Ye et al. 8095 ( IBSC) ; Yangchun City , 24 August 1956, J.H.Liu & J. Xiao 89814 ( IBSC) ; Yangdong County, 18 July 1972, X.R. Luo 874 ( IBSC), 18 July 1979, X.R.Luo 874 ( IBSC) . Guangxi: Jinxiu County, 11 November 1981, Dayaoshan Exped. 12485 ( IBK), 27 November 1981, Dayaoshan Exped. 13582 ( IBK, IBSC) ; Lingshan County, 9 October 1973, C.F.Liang 33789 ( IBK) ; Pingnan County, 31 May 1936, Z. Huang 39222 ( IBSC), November 1948, J.X.Zhong 84926 ( IBSC) ; Xingye County, 18 October 1958, Y.X.Zhong 9 ( IBSC) ; Yanshan District , 6 August 1988, G.Z.Li 12483 ( PE) .

Figures

FIGURE 1. Aristolochia austroyunnanensis. A. Habitat; B. Leaves; C. Flowers in frontal view; D. Longitudinal-section of flower (showing inside structure); E. Anthers and gynostemium. (photographed by J.Cai from Pingbian County, Yunnan)

FIGURE 2. A–C: Aristolochia austroyunnanensis. A. Leaf; B. Flower in frontal view; C. Flower in dorsal view. D–F: A. petelotii. D. Leaf; E. Flower in frontal view; F. Flower in dorsal view. G–I: A. fangchi. G. Leaf; H. Flower in frontal view; I. Flower in dorsal view. (A–C: photographed by J.Cai from Pingbian County, Yunnan; D–F: photographed by Y.H.Tong from Malipo County, Yunnan; G–I: photographed by X.X.Zhu from Dinghu District, Guangdong)