Aristolochia pseudoutriformis X.X.Zhu & J.S.Ma, 2019

Zhu, Xinxin, Li, Xiaoqin, Liao, Shuai, Li, Guodong & Ma, Jinshuang, 2019, The taxonomic revision of Asian Aristolochia (Aristolochiaceae) V: two new species from Yunnan, China, PhytoKeys 130, pp. 93-106 : 93-95

Aristolochia pseudoutriformis X.X.Zhu & J.S.Ma sp. nov. Figures 1 , 2 , 3 , 7 A–C

Type.

CHINA. Yunnan: Baoshan, Longyang District, Hundred Flowers Ridge, 98°47.38'E, 25°18.00'N, 1891 m a.s.l., 13 May 2018, X.X.Zhu ZXX18074 (holotype: CSH [CSH-0153653!]; isotypes: CSH!, KUN!).

Diagnosis.

Similar to Aristolochia utriformis S.M.Hwang ( Hwang 1981) and A. forrestiana J.S.Ma ( Ma 1989b), but differs from the former in its lamina ovate to narrowly ovate (vs. ovate-lanceolate in A. utriformis ), limb cylinder, forming obtuse angle with upper tuber, inside dark red, dense processes (vs. limb ovoid, straight extended from upper tube, inside black purple, sparse processes in A. utriformis ) and throat ca. 6 mm in diam. (vs. ca. 1 mm in diam. in A. utriformis ) and differs from the latter in its flower light yellow (vs. light brown or purple in A. forrestiana ), limb slightly asymmetric, 2-3 × 1-1.7 cm; 3-lobed, lobes triangle or wide triangle; inside dark red (vs. asymmetric, 6-8 × 1.5-2 cm; 3-lobed, lobes lanceolate; inside black purple in A. forrestiana ), as well as throat ca. 6 mm in diam. (vs. ca. 3mm in diam. in A. forrestiana ). Detailed morphological comparisons are shown in Table 1 and Figure 7 .

Description.

Semi-deciduous climbing shrubs. Stems terete. Petioles 2-5 cm long, densely pubescence; laminas ovate to narrowly ovate, 10-22 × 7-13 cm, adaxially sparsely pubescence, abaxially densely pubescence, base cordate, margin entire, apex acute; veins palmate, 2-3 pairs from base, lateral veins 3-5-paired. Flowers axillary, sometimes on stems, solitary or paired; pedicels 1.8-5 cm, densely brown villous; bractlets 1 or 2, ovate, 3-5 mm long, adaxially glabrous, abaxially densely villous. Calyx tube geniculately curved, light yellow, abaxially sparsely villous; basal tube 1.8-2.5 cm long, inside black purple at base, dark red above base, upper tube 1.2-1.8 cm long, inside dark red; limb saccate, cylinder, slightly asymmetric, 2-3 × 1-1.7 cm, forming obtuse angle with upper tuber, inside dark red, densely processes, 3-lobed, lobes triangle or wide triangle; throat ca. 6 mm in diam.. Anthers 6, oblong, ca. 1.5 mm long, adnate in 3 pairs to base of gynostemium, opposite to lobes. Gynostemium ca. 3 mm long, 3-lobed. Ovary terete, ca. 12 mm long, densely brown villous. Fruit stem ca. 4.5 cm long, sparsely puberulous. Capsule obovate-elliptic, distinctly 6-angled, sparsely puberulous on angles, ca. 6 × 2.5 cm (ca. 5 × 2.5 cm in dry specimens). Seeds ellipse, 5-6 × 3-4 mm, not winged, the adaxial surface deeply concave and the abaxial surface convex, wrinkled, both surfaces glabrous.

Phenology.

Flowering from March to May and fruiting from July to August.

Etymology.

The specific epithet refers to the similarity between the new species and A. utriformis in the morphology of flowers. The Chinese name is given as “拟囊花马兜铃”.

Distribution and habitat.

The new species is currently known to Longyang District, Baoshan, Yunnan, China. It grows in forests at an elevation of between 1890 m and 2260 m, together with Castanopsis ssp. ( Fagaceae ), Disporum sp. ( Colchicaceae ), Elytranthe albida (Bl.) Bl. ( Loranthaceae ), Nervilia tahanshanensis T.P.Lin & W.M.Lin ( Orchidaceae ), Rubus sp. ( Rosaceae ), etc.

IUCN Red List Category.

Aristolochia pseudoutriformis is known from only two populations, with fewer than five individuals at each site. Therefore, the new species is assigned a preliminary status of Vulnerable (VU D2) according to IUCN Red List Criteria ( IUCN 2012), indicating a population with a very restricted area of occupancy (typically less than 20 km2) or number of locations (typically five or fewer).

Specimens Examined.

CHINA. Yunnan: Baoshan, Longyang District, Hundred Flowers Ridge, 30 Mar 2015, X.X.Zhu & Z.X.Hua ZH026 (CSH); 20 Apr 2017, X.X.Zhu ZXX17050 (CSH); 11 Aug 2018, X.X.Zhu & J.Wang ZXX18241 (CSH, KUN).

Figures

Figure 1. Aristolochia pseudoutriformis X. X. Zhu & J. S. Ma, sp. nov. A habit B flower (lateral view) C flower (front view) D opened flower (showing the inside structure) E anthers and gynostemium F fruit. Illustration by Shizhen Qiao.

Figure 2. Aristolochia pseudoutriformis X. X. Zhu & J. S. Ma, sp. nov. A habit B leaves C flower bud D flower (lateral view) E flower (front view) F flowers G anthers and gynostemium H fruit I seeds. Photographed by Xinxin Zhu.

Figure 3. Holotype of Aristolochia pseudoutriformis X. X. Zhu & J. S. Ma, sp. nov. (CSH- 0153653).

Figure 7. A-C Aristolochia pseudoutriformis X. X. Zhu & J. S. Ma, sp. nov. A leaves B flower (lateral view) C opened flower (showing the inside structure). D-F A. utriformis S. M. Hwang D leaves E flower (lateral view) F opened flower (showing the inside structure). G-I A. forrestiana J. S. Ma G leaves H flower (lateral view) I opened flower (showing the inside structure). J-L A. yangii X. X. Zhu & J. S. Ma. J leaves K flower (lateral view) L Opened flower (showing the inside structure). Photographed by Xinxin Zhu (A-C, G-L); Photographed by Lei Cai (D-F).