Vigna Sathishiana (Fabaceae): a New Species from Southern Western Ghats, India

J. Jpn. Bot. 92(4): 193–198 (2017)

Vigna sathishiana (Fabaceae): A New Species from Southern Western Ghats, India

a, b Anoop Puthuparampil Balan *, Sreevilas Vasudevan Predeep c and Punnakkal Sreedharan Udayan

aIndian Cardamom Research Institute, Myladumpara, Idukki, Kerala, INDIA; bP.G. Department of Botany, Sree Vidyadhi Raja Nair Service Society College, Vazhoor, Kottayam, Kerala, INDIA; cP.G. Department of Botany, Sree Krishna College, Guruvayur, Thrissur, Kerala, INDIA *Corresponding author: [email protected]

(Accepted on February 24, 2017)

Vigna sathishiana A. P. Balan & S. V. Predeep, a new species of the genus Vigna Savi of the sect. Ceratotropis (Fabaceae) is described and illustrated from the southern Western Ghats of India. The diagnostic morphological characters, detailed description, illustration and images are presented with notes on habitat, ecology and conservation status.

Key words: Fabaceae, India, new species, Vigna, Western Ghats.

Vigna Savi (Fabaceae) is a large pantropical elevated to the rank of species and named Vigna genus with 104 species (Lewis et al. 2005) in indica (Dixit et al. 2011). Similarly, Aitawade et seven subgenera viz. Ceratotropis, Haydonia, al. (2012) elevated Vigna mungo var. sylvestris Lasiospron, Macrorhynchus, Plectotropis, Lukoki, Marechal & Octoual to the rank of Sigmoidotropis and Vigna (Marechal et al. species. They also added a new species to the 1978). The subgenus Ceratotropis (Piper) genus, Vigna sahyadriana Aitawade, K. V. Bhat Verdc., also known as Asian Vigna, has its centre & S. R. Yadav from the northern Western Ghats. of diversity in Asia with 21 species (Tomooka et Vigna yadavii Gaikwad, Gore, Randive & Garad al. 2002). The genus has commercial potential (Gaikwad et al. 2014) and Vigna pandeyana as sources of pulses and forage crops and has Gore, S. P. Gaikwad & Randive (Gaikwad et al. a complex taxonomy because of its complex 2015) are two other species recently discovered floral characters and close relationship with the from northern Western Ghats. Latha et al. (2014) genus Phaseolus L. Floral characteristics like described a new species, Vigna konkanensis size of keel petal pocket, twisting of beak, nature Latha, K. V. Bhat, I. S. Bisht, Scariah, Joseph of style and stigma, nature of pod trichomes, John & Krishnaraj, from the west coast of India. number, size, shape and surface nature of seeds, While exploring the legume flora of Western etc. are significant characters in determination of Ghats, the first author collected some interesting the species. Babu et al. (1987) revised the tribe Vigna specimens from the Kallar dam site of Phaseoleae for India and recognized 23 species Idukki district in Kerala state. Critical study of Vigna in the country. Recently, Vigna trilobata with the literature (Baker 1876, Gamble 1918, (L.) Verdc. var. pusilla Naik & Pokle was Verdcourt 1970, Marechal et al. 1978, Babu et al.

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Fig. 1. Vigna sathishiana A. P. Balan & S. V. Predeep. A, B. Habit. C. Stem. D. Raceme. E. Pods. F. Pod surface. G. Seed. H. Seedling. I. SEM micrograph of pollen grain. Scale bars: 1 cm (A, B, D, E, H), 5 mm (C), 3 mm (F), 2 mm (G) and 20 μm (I).

1987, Tomooka et al. 2002, Aitawade et al. 2012, V. radiata (L.) Wilczek and V. sublobata (Roxb.) etc.) and authentic specimens in various herbaria Bairiganjan, Panda, Choudhury & Patnaik, revealed that it is a novel taxon with affinity but differing in its small, slender twining habit, to Vigna radiata (L.) Wilczek var. radiata small, unlobed and sparsely hairy leaflets with and V. sublobata (Roxb.) Bairiganjan, Panda, obtuse-acute apices, 2–3-flowered racemes, Choudhury & Patnaik. Pollen morphological smaller flowers and pods, brown seeds with studies also showed significant difference from projected wavy reticulation on testa and smaller the allied taxa, and hence it is described here as a pollen grains with reticulate-heterobrochate new species. exine sculpturing.

Taxonomic treatment Type: INDIA. Kerala, Idukki district, Vigna sathishiana A. P. Balan & S. V. Kallar dam site, 09°83ʹN, 77°15ʹE, at ± 1000 Predeep, sp. nov. m, 10 Dec. 2016, Anoop P. Balan 21004 (MH– Vigna sathishiana is allied to the mung bean, holotype; MH, CALI–isotypes). August 2017 The Journal of Japanese Botany Vol. 92 No. 4 195

Fig. 2. Vigna sathishiana A. P. Balan & S. V. Predeep. A. Habit. B. Stipule. C. Bract. D. Bracteole. E. Calyx. F. Standard petal. G. Wings. H. Keels. I. Stamens. J. Pistil. Scale bars: 1 cm (A), 5 mm (H, I), 3 mm (F, J), 2 mm (B, E, G) and 1 mm (C, D).

A slender twining herb; stem 60–90 cm long, persistent; petioles 2.5–4 cm long, covered with densely covered with retrorse yellowish brown brown retrorse hairs; stipels 3–4 mm long, linear, hairs of 0.8–1.25 mm long. Leaves pinnately ciliolate; petiolules 2–2.5 mm long, sparsely 3-foliolate, 6–10 cm long including petiole and hairy; leaflets membraneous, sparsely pubescent rachis; stipules peltate, sub-medifixed, 6–8 × above, pilose below along the veins; terminal 2.5–3.5 mm, ovate-elliptic, rounded at base, leaflet 3–4.5 × 2–3.5 cm, ovate-rhomboidal, acute at apex, margins ciliate, 6–8-veined, obtuse-rounded at base, obtuse-acute at apex; 196 植物研究雑誌第 92 巻第 4 号 2017 年 8 月

Table 1. Major morphological differences between Vigna sathishiana and its allied species Character V. sathishiana V. radiata var. radiata V. sublobata Habit slender twining herb, 60–90 erect herb, 30–50 cm high robust twining herb, 120– cm long 200 cm long Stem densely covered with densely covered with 2–3 densely covered with 2–3 retrorse, yellowish brown mm long grey hairs mm long brown hairs hairs of 0.8–1.25 mm long Stipules 6–8 × 2.5–3.5 mm, ovate- 8–12 × 5–7 mm, ovate 8–12 × 5–6 mm, ovate elliptic Stipels 3–4 mm long 5–6 mm long 5–8 mm long Leaves 6–10 cm long; leaflets 12–18 cm long; leaflets 20–30 cm long; leaflets obtuse-acute at apex, never acute-acuminate at apex, acute-acuminate at apex, lobed, sparsely pilose sometimes 3-lobed, sometimes 3-lobed, beneath densely hirsute-tomentose densely hirsute-tomentose beneath beneath Racemes 6–12 cm long, 1–3-flowered 4–6 cm long, 4–6-flowered 8–20 cm long, 5–8-flowered Flowers 0.8–1 cm long 1.5–1.8 cm long 1.8–2.2 cm long Standard petal 8–10 × 12–14 mm 9–11 × 16–18 mm 10–12 × 18–20 mm

Wing petal 8–10 × 5–6 mm 14–16 × 8–10 mm 15–17 × 8–10 mm

Keel petal 10–12 × 5–6 mm; 14–16 × 5–6 mm; lateral 16–18 × 5–7 mm; lateral lateral pocket 1–1.5 mm pocket 3–4 mm long pocket 4–5 mm long long Pods 1–3 per infructescence; 3–4 4–6 per infructescence; 5–8 per infructescence; × 0.3–0.35 cm; covered 5.5–6.5 × 0.4–0.5 cm, 6–6.5 × 0.5–0.6 cm, with appressed brown ferruginously hairy with ferruginously hairy with hairs of 0.4–0.8 mm long 0.6–1 mm long hairs 0.6–1 mm long hairs Seeds 8–10, ca. 3 × 2 × 2 mm, 10–14, ca. 3.5 × 3.5 × 2.5 10–14, ca. 3 × 2.8 × 2.4 mm, tetragonous, parrot green mm, rectangular, green, rectangular, dark brown, turning to brown when testa glossy with obscure testa rough with projected matured, testa rough with reticulation. reticulation projected wavy reticulation Pollen Polar Axis (PA) 37.62 μm (36.47–40.17 μm) 46.48 μm (45.25–47.96 μm) 48.25 μm (45.86–51.42 μm) Equatorial diameter (ED) 36.24 μm (35.15–37.46 μm) 44.64 μm (42.65–47.24 μm) 44.46 μm (41.98–45.86 μm) PA/ED 1.03 μm 1.04 μm 1.08 μm Porus diameter 7.01 μm (6.68–7.24 μm) 8.52 μm (7.95–8.92 μm) 8.18 μm (7.25–8.76 μm) Pollen shape in equatorial view prolate-spheroidal prolate-spheroidal prolate-spheroidal Pollen shape in polar view circular elliptical elliptical Exine surface reticulate-heterobrochate reticulate-homobrochate reticulate-homobrochate lateral leaflets 2.8–3.5 × 2–2.6 cm, obliquely campanulate, pale brown, puberulent; tube ca. 2 ovate. Racemes axillary, 6–12 cm long, mm long; lobes 0.8–1 × 0.8–1 mm, deltoid, ciliate 1–2(–3)-flowered; peduncles 4–10 cm long, at margins, upper two lobes connate except at sparsely retrorse hairy; rachis 0.8–1.5 cm long the tip. Standard petal asymmetrical, 8–10 × 12– with flowers crowded at apex. Flowers 0.8–1 cm 14 mm, obliquely elliptic, emarginate at apex, long, subsessile, pale yellow; bracts 2–2.5 × 1 claw 1–1.5 mm long, auricles ca. 1 mm long; mm, ovate, margins ciliate, deciduous; bracteoles wings 8–10 × 5–6 mm, obliquely obovate, claw 3–3.5 × 1 mm, lanceolate, ciliolate. Calyx ca. 1.5 mm long, auricles ca. 1 mm long; keels August 2017 The Journal of Japanese Botany Vol. 92 No. 4 197

10–12 × 5–6 mm, incurved, beak not spirally taxon is in honor of Dr. C. Sathish Kumar, twisted, claw 1.5–2 mm long, lateral pockets Javaharlal Nehru Tropical Botanic Garden & 1–1.2 mm long. Stamens diadelphous; staminal Research Institute, Thiruvananthapuram, Kerala, sheath 7–8 mm long; filaments 5–6 mm long, for his immense contributions to Indian plant filiform; anthers ac . 0.3 × 0.2 mm. Ovary sessile, taxonomy, especially in the field of Orchid 4–5 × 1 mm, densely pilose, 8–10-ovuled; style systematics. 8–10 mm long, hairy towards upper half and prolonged beyond stigma to form a beak of 0.2– The authors are grateful to the curators of 0.3 mm long. Pods straight, 3–4 × 0.3–0.35 cm, BM, E, K, L, LINN, MNHN, S, etc. for the subcylindrical, covered with appressed brown virtual images of type specimens and CAL, hairs of 0.4–0.8 mm long, 8–10-seeded. Seeds CALI, KFRI, MH and TBGT for permitting 8–10, 3 × 2 × 2 mm, tetragonous, parrot green to consult specimens. Special thanks are due turning to brown when matured, testa rough to Mr. K. M. Shameem, University of Calicut, with projected wavy reticulation; aril absent. Malappuram for photomicroscopic images. Germination epigeal. Pollen: 3-zonoporate; ora lalongate (3.8 × References 5.2 µm), membrane smooth; prolate-spheroidal Aitawade M. M., Sutar S. P., Rao S. R., Yadav S. R. and in equatorial view and circular in polar view; Bhat K. V. 2012. Section Ceratotropis of subgenus average grain size 37.62 × 36.24 µm (36.47– Ceratotropis of Vigna (Leguminosae-Papilionoideae) 40.17 × 35.15–37.46 µm); exine surface in India with a new species from northern Western Ghats. Rheedea 22(1): 20–27. reticulate, heterobrochate. Babu C. R., Sharma S. K. and Johri B. M. 1987. Flowering and fruiting: October–December. Leguminosae-Papilionoideae: Tribe-Phaseoleae. Bull. Distribution: So far known only from the Bot. Surv. India 27: 1–28. type locality, Kallar dam site of Idukki district in Baker J. G. 1876. Vigna Savi. In: Hooker J. D. (ed.), The Kerala, India. Flora of British India 2: 200–207. Reeve and Co., London. Conservation status: The present conservation Dixit T. M., Sutar S. P., Yadav S. R., Bhat K. V. and Rao S. status is data deficient. However, only one R. 2011. Vigna indica, a new name for Vigna trilobata population of the species with six mature plants var. pusilla and a note on section Aconitifoliae in India. were found. The type locality is out of protected Rheedea 21(1): 1–7. Gamble J. S. 1918. The Flora of Presidency of Madras 1: reserve forest and the plants are under threat 361–365. Adlard and Son Ltd., London. especially due to human activities, animal Gaikwad S., Gore R., Randive S. and Garad K. 2014. Vigna grazing and grassland fires. yadavi (Leguminosae: Papilionoideae), a new species Habitat and ecology: The species grows in from Western Ghats, India. Biodiversity Data J. 2: open grasslands in moist hill slopes at 1000 m e4281. Gaikwad S., Gore R. and Randive S. 2015. Vigna elevation above sea level. Grows as a twiner pandeyana (Fabaceae), a new species from northern on shrubs and tall grasses usually in association Western Ghats, India. Biodiversity Data J. 3: e4606. with other legumes like Crotalaria humifusa Latha M., Sheen Scariah., Krishnaraj M. V., Graham ex Benth., C. retusa L., C. salicifolia Presannakumari K. T., Bhat K. V., Bisht I. S. and Joseph John K. 2014. Vigna konkanensis (Fabaceae: Heyne ex Wight & Arn., Smithia blanda Wall. Papilionoideae) a new species from the west coast of ex Wight & Arn., Tephrosia tinctoria Pers. etc., India. Webbia 69(1): 49–52. and grasses like Apluda mutica L., Cymbopogon Lewis G., Schrire B., MacKinder B. and Lock M. (eds.) flexuosus (Nees ex Steud.) Wats., Pennisetum 2005. Legumes of the World. Royal Botanic Gardens, polystachyon (L.) Schult., Themeda triandra Kew. Marechal R., Mascherpa J. M. and Stainer F. 1978. Etude Forssk., etc. taxonomique d’un groupe complex d’ species des Etymology: The specific epithet of the new generes Phaseolus et Vigna (Papilionaceae) sur la base 198 植物研究雑誌第 92 巻第 4 号 2017 年 8 月

de donnees morphologiques et polliniques traitees par Publishers, London. l’anyse informatique. Biossiera 28: 1–273. Verdcourt B. 1970. Studies in the Leguminosae- Tomooka N., Vaughan D. A., Moss H. and Maxted N. Papilionoideae for the ‘Flora of Tropical East Africa’: 2002. The Asian Vigna: Genus Vigna subgenus IV. Kew Bull. 24(3): 507–569. Ceratotropis genetic resources. Kluwer Academic

a b c A. P. Balan , S. V. Predeep , P. S. Udayan ：インド・西ガーツ山脈南部からの 1 新種，Vigna sathishiana（マメ科）マメ科ササゲ属 Ceratotropis 節の 1 新種，Vigna 花をつけ，花と果実が小型で，種皮に細かく隆起した皺 sathishiana A. P. Balan & S. V. Predeep をインド・西ガのある褐色の種子をもつこと，また花粉粒が小型で外壁ーツ山脈南部から記載した．本種はケララ州 Idukki の模様が異なる．地方から得られたもので，V. radiata (L.) Wilczek や（aインド・Indian Cardamom Research Institute, V. sublobata (Roxb.) Bairiganjan, Panda, Choudhury & bインド・Sree Vidyadhi Raja Nair Service Society College, Patnaik に近いが，全体小型でつる性となり，小葉は全 Department of Botany, 縁で鈍頭〜鋭頭でまばらに毛があり，総状花序は 2–3 cインド・Sree Krishna College, Department of Botany）