Vincetoxicum kenouriense (Wight) Wight, Icon. Pl. Ind. Orient., pl. 1614. 1850

Shah, Sayed Afzal, Sultan, Amir, Wen, Jun, Ullah, Zahid, Nisa, Surat Un, Ren, Zhumei, Alam, Muhammad Maqsood, Iqbal, Javed & Mumtaz, Abdul Samad, 2021, Taxonomy of Vincetoxicum s. str. (Asclepiadoideae, Apocynaceae) from southern Asia including three new species and resurrected names, PhytoKeys 179, pp. 35-73 : 35

5. Vincetoxicum kenouriense (Wight) Wight, Icon. Pl. Ind. Orient., pl. 1614. 1850 Figs 2O, P , 3E , 4G, H , 10 , 11 , 12

Cynanchum kenouriense Wight, Contr. Bot. India 58. 1834.

Type.

India. Kenour, Royle 18 (Holotype K! [K000872737]) .

Undershrubs, up to 1 m tall. Stem pubescent all around or along 2 dense lines, internodes 2-13 cm long. Leaves opposite; petioles 1-10 (-14) mm long, equally pubescent all around or sometimes denser along adaxial channel, lamina strongly discolorous, narrow to broadly ovate, 4-10 × 1.8-6.5 cm; apex narrowly acute to very shortly acuminate; base round to sub-cordate to sub-truncate; venation including tertiary and quaternary veins prominent, more prominent and raised on abaxial surface, secondary veins up to 14 on each side of midvein, trichomes absent on both surfaces, sometimes sparsely present on tertiary and quaternary veins, midrib and secondary veins densely pubescent on both surfaces, margins pubescent. Inflorescences mostly sessile, rarely both sessile and short-pedunculate inflorescences present on the same plant, peduncles up to 1.5 cm; bracts linear, up to 2 mm long, pubescent; pedicels 2-8 (-10) mm long, pubescent all around, sometimes pubescent along one or two longitudinal lines. Flowers yellowish-green to green, 4-5 × 2-2.5 mm; sepals tapering to acute or narrowly acute apices, up to 2 mm long, margins sparsely ciliate, calycine colleters 5 or 10 per flower; corolla tube ca. 1 mm long, lobes oblong with obtuse apices, 3-3.5 × 1-2 mm, glabrous within or sparse caducous trichomes present; corona lobes long-triangular with acute apex, slightly divergent, ca. 1 × 0.8 mm, exceeding slightly the length of the gynostegium. Follicles fusiform, up to 7 × 1 cm, apex long-acuminate, surface glabrous, slightly striate. Seeds brown, 6-7 × 3-3.5 mm, wings less than 1 mm broad; coma 2-3 mm long.

Distribution and habitat.

Endemic to a long geographic range in the Hindukush Himalayas from Bhutan in the east to Pakistan in the west. The western limit of this species is district Swat (Khyber Pakhtunkhwa province), Pakistan. It occurs on higher elevations between 1500 and 3000 m. The habitats of the species are commonly the Himalayan moist temperate forests (evergreen forests of conifers between 1500 to 3000 m elevations), rarely subalpine or open alpine lands (above 3000 m). We collected it from open stony alpine slopes and stream side slopes in a V-shaped mountain valley. The associated vegetation was either alpine herbs or conifers, and herbaceous to shrubby flora.

Phenology.

Flowering from May to August and fruiting from August to October.

Provisional conservation status.

Least concern (Table 1 ). Although having highly clumped, distant populations, Vincetoxicum kenouriense spans a wide range in the Hindukush Himalayas. It is confined to higher altitudes and faces almost no natural threats. Anthropogenic activities, however, are deemed as a potential threat. For instance, two of its populations in Pakistan (in district Bagh, AJK, and district Swat, Pakistan) were found in recreational areas that are expected to undergo changes in the near future which might result in destruction of its habitats. It was also collected previously from Changla Gali (district Abbotabad, Pakistan). In spite of several visits in the past decade, we could not find it anymore in that area. These observations suggest that recreational activities might prove a potential threat to its existence, at least in Pakistan.

Notes.

Vincetoxicum kenouriense was described by Wight (1834) from Kenour (India). Hooker (1883) synonymized it with Cynanchum vincetoxicum (syn. V. hirundinaria ). Hooker’s treatment has been followed in major floras ( Stewart et al. 1972; Ali and Khatoon 1982) resulting in a broader circumscription of V. hirundinaria . In the present treatment, V. kenouriense is reinstated and presented as a new record for the Flora of Pakistan, Nepal and Bhutan. It replaces V. hirundinaria in southern Asia.

Specimens examined.

Bhutan. Thimpu: Paro ( West Bhutan ), 7800 ft., 27 June 1933, F. Ludlow & G. Sherriff 158 (BM [BM001119300]) .

India. Uttarakhand: Garhwal, Mussoorie, Kidar Kantha , 13000 ft., 09 April 1952, J.R. Drummond 22753 (K); Hab. Sikkim, 7000-10,000 ft., s.d., J.D. H[ooker] s.n. (GH, [GH01147527]); Daya-Balsan state, Simla hills, 7500 feet, 12 June 1937, G.E. Parkinson 7386 (RAW); Dharmsala [India], 17 June 1929, [R.R. Stewart] s.n. (RAW [acc. # 1004]); s.loc., s.d., H. Falconer s.n. (GH [GH01147530]); Himalaya Bor. Oce., 4000-5000 ft., s.d., W. Griffith 3760 (GH [GH01147532]) .

Kashmir: B-8 above Gulmarg, 9000-10,000 ft., 31 July [18]92, J.F. Duthie s.n. (K); Basaoli, 8000 ft., s.d., C.B. Clarke 31523A (K); Tanmarg near Gulmarg, Kashmir, 02 September 1929, R.R. Stewart 13100 (RAW); Sonamarg, 9000 ft., s.d., R.R. Stewart 7306 (K); Below Sonamarg, Sindh Valley, 8000-9000 ft., 02 September 1940, R.R. Stewart 21328 (RAW, US); Gulmarg to Khaipur, 21 July 1890, J.F. Duthie s.n. (RAW [acc. # 1005]); Duksum-Kokernagh [Kashmir], 3000 m, s.d., G.A. Shapu 201 (KASH); Slopes above Harwan [Kashmir], 2300 m, s.d., G. Singh 833 (KASH).

Nepal. Gandaki Zone: Manang Distr. Pisang (3090 m), Humre (340 m), Manang (3360 m), 16 August 1994, M. Mikage, N. Fujii, T. Kajita, N. Kondo, S. Noshiro & K.Yoda, 9485444 (GH) ; Mustang District: Gnyu Pass (4100 m), Chhengar (3700 m), Muktinath (3650 m), 14 July 2000, Y. Lokawa, M.N. Subedi, Y. Takashi & K. Kano 20020202 (GH); On descendant and l’lmja-Khola, 3100 m, 09 April 1952, A. Zimmermann 714 (K); Baghmati zone, before Syarpagaon, north side of Lantang River , 2600 m, 19 September 1966, D.H. Nicolson 2445 (US) ; Bagmati zone: south of Gossainkunde, Blumche , 2500 m, 12 May 1967, D.H. Nicolson 3339 (US) .

Pakistan. Khyber Pakhtunkhwa: B-7 Hazara, Kaghan valley, 9800 ft., 09 July 1897, Inayat 19940 (K); Nathia, July 1907, H. Deane s.n. (K); Mundi, UNA forest, Siran Valley , District Mansehra, 13 June 1994, Q. Marwat 425 (RAW); C-7 Murree Hills Changlagali, 8000 ft., M. Nath 336 (RAW); Azad Jammu and Kashmir: Bagh, 19 June 1956, collector unknown 1507 (KUH); Bagh, Sudhan Gali to Ganga Choti , 2500-2800 m, 01 August 2016, S.A. Shah & L. Ahmad SAS-37 (RAW, US); Bagh, Poonch, 19 June 1956, M.A. Kazmi 1507 (RAW); C-8 Azad Kashmir, Poonch, near Trappar, below Kali, 17 September 1952, A.R. Khan s.n. (RAW [acc. # 998]); Raikot to Aliabad (Azad Kashmir), ± 7000 [ft], 28 June 1952, R.R Stewart & E. Nasir 23868 (KUH); Azad Kashmir, 8000 ft., 9 August 1969, Shariq 8102 (PFI); Pir Kanthi, Uri Range, 9000 ft., 17 October 1955, J. Mohammad s.n. (RAW) .

Figures

Figure 2. Outlines of leaves of southern Asian Vincetoxicum. All illustrated specimens are housed at RAW. The first image in each pair corresponds to the adaxial surface and the second to the abaxial surface. All leaves have been taken from the middle of the stem A, B Vincetoxicum sp. aff. arnottianum from S. A. Shah SAS- 9 C, D Vincetoxicum sp. aff. arnottianum from S. A. Shah SAS- 46 E, F Vincetoxicum sp. aff. arnottianum from R. Khan SAS- 41 G, H V. arnottianum from S. A. Shah & F. Rahman SAS- 3 I, J V. arnottianum from S. A. Shah & B. Ali SAS- 4 K, L V. cabulicum from D. Podlech 15814 M, N V. cardiostephanum from S. A. Shah, M. Turi et al. SAS- 40 O, P V. kenouriense from S. A. Shah & L. Ahmad SAS- 37 Q, R V. lenifolium from S. A. Shah SAS- 44 S, T V. luridum from S. A. Shah & I. Ahmad SAS- 23 U, V V. lenifolium from N. Ali 1029 W, X V. sakesarense from I. Ahmad 27821 Y, Z V. stewartianum from R. R. Stewart 16709 AA, AB V. stocksii from B. Gul, N. Khan et al. SAS- 21 AC, AD V. subcanescens from A. Sultan, Z. Saqib et al. SAS- 52 AE, AF V. subcanescens from S. A. Shah & A. Ullah SAS- 8. Drawing by M. Saleem and S. A. Shah.

Figure 3. Illustration of corona types observed in southern Asian Vincetoxicum. The dark coloured shapes show corona lobes A Vincetoxicum arnottianum from S. A. Shah & B. Ali SAS- 4 (RAW) B V. cabulicum from W. Koelz 11764 (US) C V. cardiostephanum from S. A. Shah, M. Turi et al. SAS- 40 (RAW) D V. glaucum from W. Dudeeon & L. A. Kenoyer 56 (MO) E V. kenouriense from S. A. Shah & L. Ahmad SAS- 37 (RAW) F V. lenifolium from S. A. Shah SAS- 44 (RAW) G V. luridum from S. A. Shah & I. Ahmad SAS- 23 (RAW) H A variable specimen of V. lenifolium from N. Ali 1029 (RAW) I V. sakesarense from I. Ahmad 27821 (RAW) J V. stewartianum from R. R. Stewart 16709 (RAW) K V. stocksii from J. F. Duthie 18918 (RAW) L V. subcanescens from S. A. Shah & A. Ullah SAS- 8 (RAW). Drawing by M. Saleem and S. A. Shah.

Figure 4. Pollinaria of southern Asian Vincetoxicum A, B V. arnottianum C V. cabulicum D, E V. cardiostephanum F V. glaucum G, H V. kenouriense I, J V. lenifolium K, L V. luridum M V. lenifolium N, O V. sakesarense P V. stewartianum Q, R V. stocksii S, T V. subcanescens.

Figure 10. Field photographs of Vincetoxicum kenouriense A habit B, C flowers D follicles. Photos by Zahid Ullah and S. A. Shah.

Figure 11. Vincetoxicum kenouriense illustrated by S. A. Shah and S. U. Nisa from S. A. Shah & L. Ahmad SAS- 37 (RAW!) A flowering plant B corolla lobes C corona (black) D follicle.

Figure 12. Geographic distribution of Vincetoxicum kenouriense.