Vincetoxicum cabulicum (Bornm.) Bornm. ex S.A. Shah

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

2. Vincetoxicum cabulicum (Bornm.) Bornm. ex S.A. Shah Figs 2K, L , 3B , 4C , 7

Cynanchum cabulicum Bornm., Bot. Jahrb. Syst. 66: 233. 1934.

Type.

Afghanistan. On Mt. Babour , 1800 m, 1 May 1929, Manger s.n. "flowers yellowish-green, inconspicuous" (holotype B., destroyed). Neotype, designated here : Afghanistan. Paghman , 7500 ft., dry slope; clumps; 3 ft. high; flr. greenish, often tinged madder; 26 June 1937, W. Koelz 12076 ( US! [ US 03264725]) .

Undershrubs, ca. 45 cm tall. Stem striate, sub-canescent all around, internodes 2.5-7 cm long. Leaves subsessile, rarely petiolate; petioles 3-8 mm long, sub-canescent all around; lamina discolorous, narrow to broadly ovate, 3-7 × 2-4.5 cm, both surfaces including veins and margins sub-canescent; apex acuminate; margins smooth; base sub-cordate-round; veins visible on both surfaces, secondary veins up to 8 on each side of midvein. Inflorescences sessile or pedunculate; peduncles 1-2 cm long; bracts minute, ca. 1 mm long, margins ciliate; pedicels 3-6 mm long, sub-canescent; sepals tapering to acute apices, sub-canescent, ca. 1 mm long; corolla purple, corolla tube 1 mm long, lobes oblong-ovate, straight, 2-2.5 mm × 1-1.5 mm, pubescent within; corona lobes obovate, ca. 0.7-1 × 0.5 mm, divergent, as long as gynostegium. Follicles fusiform, ca. 5.3 × 1.3 cm. Seeds not seen.

Distribution and habitat.

Endemic to northern Afghanistan. The data on herbarium labels suggest that V. cabulicum grows in clumps on dry slopes of mountains. The elevation range is 1500 to 2800 m.

Phenology.

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

Provisional conservation status.

Vulnerable (Table 1 ). Vincetoxicum cabulicum is collected from a few locations in Afghanistan and appears to be clumped in distribution. There are no reports on grazing. However, a possible threat appears to be habitat destruction through anthropogenic activities.

Notes.

This species was originally described as Cynanchum cabulicum by Bornmüller (1934). In the description, Bornmüller refers to "Syn. Vincetoxicum cabulicum Bornm. herb.", thus creating an invalid name. Here, the name is validated as Vincetoxicum cabulicum (Bornm.) Bornm. ex S.A. Shah. Rechinger (1970) lumped this species with V. glaucum and, in turn, Ali and Khatoon (1982) lumped the latter with V. canescens . Vincetoxicum glaucum is hereby recognized as a separate species (see more comments on this complex below V. subcanescens ).

Vernacular name.

Rang Koh-e-Sabz (Pashto).

Specimens examined.

Afghanistan. Kabul: Paghman, near Kabul, 7000 ft., 193[0s], F. Howland specimen B. (US [US03264726); Westhang des Koh-i-Sher Darwasa bei Kabul , 2100 m, 10 July 1969, D. Podlech 15814 (RAW); Chandau , 8000 ft., 07 June 1937, W. Koelz 11764 (US); In Valle Paghman, Kabul, ca. 34°36'N, 68°56'E, 2300-2800 m, s.d., K.H. Rechinger 17141 (US, MO); Kabul, in declivibus borealibus montis Scher Darwasa, ca. 34°30'N, 69°10'E, 1800-1900 m, s.d., K.H. Rechinger 16986 (US); Paghman, 8000 ft., 22 June [19]35, W.R. Henry 273 (K) ; Badakhshan: Faisabad district , 5000 ft., 22 May 1964, P. Furse 6247 (K) .

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 7. Geographic distribution of Vincetoxicum cabulicum, V. glaucum and V. subcanescens.