Mucuna guangxiensis, a new species of Mucuna subg. Macrocarpa (Leguminosae-Papilionoideae) from China Author Jiang, Kaiwen Key Laboratory of Biodiversity Conservation in Southwest China, State Forestry Administration, Southwest Forestry University, Kunming, Yunnan 650224, China. Author Huang, Yunfeng Guangxi Institute of Traditional Medical and Pharmaceutical Sciences, Guangxi 530022, China. Author Moura, Tânia M. Departamento de Ciências Biológicas, Instituto Federal Goiano, Rod. Geraldo Silva Nascimento, Km- 2,5, Urutaí, GO 75790 - 000, Brazil. text Phytotaxa 2020 2020-02-17 433 2 145 152 http://dx.doi.org/10.11646/phytotaxa.433.2.5 journal article 10.11646/phytotaxa.433.2.5 1179-3163 13874994 Mucuna guangxiensis K.W. Jiang & Y.Feng Huang , sp. nov. ( 广®油Ǝff ), Fig. 1 & 2 Type:— CHINA . Guangxi Zhuang Autonomous Region: Nanning Prefecture ( ø Ṫ 市 ), Mashan County ( Ḽ 山县 ), Baishan Town ( Ů 山 ¢ ), 13 th April 2019 (fl.). Huang Yun-Feng & Huang Yun-Dong 31405 ( holotype CSH !, isotypes CSH !, GXMI !, SWFC !) Diagnosis: — Mucuna guangxiensis is similar to Mucuna birdwoodiana with yellowish or greenish white color of petals, but it can be distinguished from the latter one in leaflets with dense sericeous hairs on the abaxial surface (vs. glabrous or with sparse hairs on the abaxial surface) and the longer fruits (up to 70 cm ) with short yellow erect hairs but without caducous bristles and paired wings along the both margins (vs. fruits up to 45 cm , with dense, spreading, dark brown or red-brown pubescence and caducous bristles; both margin with a pair of wings). It is also similar to Mucuna macrocarpa with the woody legumes with irregular longitudinal wrinkles when dry, but the petals are totally yellowish or greenish white in M. guangxiensis (vs. the standard is white while the wings and keels are purple). Description: —Large woody twinning liana up to 15 m long. Old stems canaliculate when dry; bark grayish brown, lenticellate; cross-section with red liquid. Branches slender, sparsely with adpressed or ± spreading pubescent hairs, canaliculate. Leaves 27‒38 cm long; petiole 11‒21 cm long, with a pulvinus ca. 1 cm long at base, sparsely covered with adpressed or ± spreading, pale or somewhat yellowish-brown pubescent hairs similar to which on the branches, with more dense hairs at base; stipules and stipels absent; petiolules 6‒7 mm , densely with adpressed yellowish sericeous hairs; rachis 3.5‒5.5 cm , with indumentum similar to petiole; leaflets thinly papyraceous or papyraceous, with abundant of adpressed pale pubescence on the adaxial surface, more dense on veins, abaxial surface with denser and longer grayish white sericeous hairs, ± spreading; lateral veins usually 6‒7 pairs, somewhat curved at apex; terminal leaflet broadly rhombic ovate to broadly ovate, 7.0‒9.3 × 11.3‒17 cm , base broadly cuneate or somewhat truncate, apex usually acuminate with an acumen ca. 4 mm long, rarely obtuse or emarginate; lateral leaflets rather asymmetrical, with the ratio of abaxial to adaxial halves 1.66‒2.20, 8.3‒15.1 × 6.5‒10.3 cm , base truncate or somewhat broadly cuneate, apex similar to which of terminal leaflet. Inflorescence a pseudoracemose, usually arising from old stems, the axis 1‒10 cm long, canaliculate, densely with adpressed or spread minute brown hairs, with 2‒3 flowers per node, the nodes spiral, the internodes 7‒15 mm long; bracts and bracteoles caducous, not seen on the specimens; pedicel ca. 1.2 cm , with dense pale pubescent hairs and sparse yellow bristles (ca. 1 mm long). Flowers 6.5‒8.0 cm long. Calyx with dense minute spreading hairs and sparse yellow caducous bristles on the outer surface, with dense adpressed hairs on the inner surface; tube ca. 17 × 8‒9 mm ; the adaxial lobe formed by two entirely connate sepals, ca. 20 × 5 mm , lateral lobes ca. 5 × 5 mm , the lowest ca. 5 × 8 mm , all lobes with an acute apex. Corolla yellowish or greenish white, nigrescent when dry, each petals with a somewhat ciliate apex, standard 2.7‒3.4 × 3.0‒ 3.3 cm , glabrous, rounded at apex, with claw and auricles at base, claw 6‒7 mm , auricle ca. 0.3 mm ; wings ca. 6 × 1.3 cm , obtuse at apex, with claw and auricle at base, adaxial surfaces densely with spread minute hairs around the base, claw 0.9‒10 cm , auricle ca. 5 mm ; keels 6.0‒7.0 × 0.8‒1.1 cm , glabrous, apex at ca. ⅓ of the length curved, with an apex horny ca. 1 cm , base with a claw, 0.6‒1.0 cm, auricle absent. Stamens 10, diadelphous, 9+1, with 1 free and the other 9 fused at 80% of the of filaments length to form a staminal tube, dimorphic with 5 larger, sub-basifixed anthers and 5 smaller, dorsifixed anthers (including the anther on the free stamen). Gynoecium somewhat longer than stamens, ca. 9 cm , with only one carpel; ovary linear, sessile, ca. 2.5 cm long, with conspicuous groove when dry, densely with pale hairs; style ca. 5.5 cm , linear, rather sparsely covered with ± spread hairs; stigma terminal. Fruit a large woody legume, linear, 22‒70 × 4.5‒5.5 cm , not or ± constrict between seeds, the outer surface of valve densely with yellowish brown pubescence, somewhat caducous when old, bristles not seen, with longitudinal wrinkles near the margins, sometimes with a stipe at base, beaked at apex, dehiscent along one or both sutures, if dehiscent along both sutures, valves sometimes coiling after opening. Seeds 6‒15 per pod, dark brown to black, compressed, surrounded by a sponge seed stalk when in legume, ca. 3.0 × 2.5 × 0.8 cm , hilum black, length ca. ⅘ of the seed circumference. Distribution and ecology: — Mucuna guangxiensis is only known from the type locality, Mashan Town in Nanning, Guangxi ( Fig. 3 ). It occurs at the elevations of ca. 250 m , in the sparse forest from the foot to the mountainside of stone mountains. Phenology: —Flowering March to April, fruiting September to October. Etymology: —The Latin epithet is given here as guangxiensis , which refers to the type locality of this species, Guangxi Province . The Chinese name “ 广®油Ǝff ” is also derived from the Latin name, “ 广® ” is the Chinese character writing of Guangxi , while “ 油Ǝff ” is the Chinese common name for the genus Mucuna . Vernacular name: —In the local Vahcuengh of the type locality, the new species is called as “gaeu-nuem”( 坵¥ ), which means “python vine” in English. Conservation status: —We do not have adequate information to make the conservation assessment of Mucuna guangxiensis , therefore, we consider this species as Data Deficient (DD) for a while according to the IUCN criteria ( IUCN 2014 ). Taxonomic notes: — Moura et al. (2016a) provided four main diagnostic characteristics for Mucuna subg. Macrocarpa : (1) ovary (1‒) 2‒3 cm long (vs. 0.5‒1.4 cm long for the other two subgenera); (2) ovules (4‒)9‒18 per ovary (vs. 1‒5(‒10) for the other two subgenera); (3) fruit linear, length at least 6 times width, epicarp woody, usually somewhat wrinkled but otherwise lacking any ornamentation (vs. relatively broader, epicarp leathery, usually ornamented by lamellae, ribs or rarely ± wrinkled or lacking ornamentation in M. subg. Mucuna and epicarp fleshy in M. subg. Stizolobium ); (4) fruits are usually 30‒60 cm long and up to 18-seeded. The characteristics of Mucuna guangxiensis is in line with the diagnose: ovary ca. 2 cm long; ovules 6‒15 per ovary (we did not observe the actual amount of ovules in ovary, the amount here is reference the amount of seeds in legume); fruit linear, length usually more than 6 times width (some short fruits do not meet this standard), epicarp woody, wrinkled; fruits 22‒70 cm long, up to 15-seeded. The differences between M. guangxiensis , M. birdwoodiana and M. macrocarpa are summarized in Table 1 . TABLE 1. Morphological differences between Mucuna guangxiensis , M. birdwoodiana , and M. macrocarpa .

Character	M. guangxiensis	M. birdwoodiana	M. macrocarpa
Texture of leaflets	thinly papyraceous or papyraceous	sub-coriaceous	papyraceous or coriaceous
Indumentum on the adaxial surface	with abundant of adpressed pale pubescence	glabrous or sparsely with short hairs	glabrous or with grayish white or reddish adpressed pubescence
Indumentum on the abaxial surface	densely with grayish white sericeous hairs	glabrous or sparsely with short hairs	with ferrugineous, spreading, often dense hairs
Color of the corolla	greenish or yellowish white	greenish or yellowish white	bi-colored, with standard greenish or pinkish white, wings dark purple, keel lighter mauve or yellowish green
Length of flowers	6.5‒8.0 cm	7–8.5 cm	5.5–6(–7) cm
Legume shape	not or ± constrict between seeds	torulose	markedly constrict between seeds
Indumentum on the outer surface of the legume	densely with yellowish brown pubescence, somewhat caducous with age	with a dense, spreading, dark brown or red-brown pubescence and caducous bristles	densely pubescence, rarely glabrous with age
Legume margin	without wings or any distinct thickened rim or central groove along the sutures	with a pair of wings along both sutures	without wings or any distinct thickened rim or central groove along the sutures
Ornamentation on the outer surface of the legume when dry	with longitudinal wrinkles near the margins	smooth	with irregular longitudinal wrinkles

Additional specimens examined ( paratypes ): — CHINA . Guangxi Province : Nanning Prefecture , Mashan County , Baishan Town , 20 th April 2018 (fr.). Huang Yun-Dong 01 ( CSH !) ; Nanning Prefecture , Mashan County , Baishan Town , 27 th September 2018 (fr.). Huang Yun-Dong 01 ( CSH !, GXMI !) .