Convolvulus leiocalycinus Boiss., Diagn. Pl. Orient. 7: 28. 1846. (Boissier 1846: 28).

Wood, John R. I., Williams, Bethany R. M., Mitchell, Thomas C., Carine, Mark A., Harris, David J. & Scotland, Robert W., 2015, A foundation monograph of Convolvulus L. (Convolvulaceae), PhytoKeys 51, pp. 1-282 : 105

70. Convolvulus leiocalycinus Boiss., Diagn. Pl. Orient. 7: 28. 1846. (Boissier 1846: 28). Figure 10, t. 1-8

Type.

IRAN, "In rupestris apricis. inter Abuschir et Schiras", Kotschy 39 (lectotype G, designated by Sa’ad. 1967: 67); isolectotypes E!, GOET, K!, OXF!, P!, W!).

Description.

Intricately branched spiny shrub reaching 1 m in height; branches woody, finely appressed sericeous, small stem spines present. Leaves shortly petiolate, 1-2.4 × 0.5-0.9 cm, variable in shape, oblong, lanceolate, ovate or suborbicular, acute, entire, base cuneate, truncate or auriculate, glabrous, pubescent or sericeous; petioles 2-4 mm. Flowers axillary, pedunculate, solitary; peduncle 1-10 mm, stout, woody; bracteoles minute, c. 1 mm, squamose, caducous or absent; pedicels 2-7 mm, compressed, finely pubescent, often not differentiated from peduncle; sepals lax, somewhat scarious, 4-7 × 2.5-5 mm, ovate or broadly elliptic to obovate, obtuse or acute, obviously veined or not, somewhat scarious, becoming more or less erect and adpressed to capsule in fruit or spreading or reflexed; corolla 2-3 cm long, white or pinkish, unlobed, midpetaline bands pilose near the tips only; filaments glandular below; ovary pubescent or glabrous; style glabrous, divided c. 10 mm above the base, stigmas c. 2 mm. Capsule glabrous; seeds glabrous, smooth. [ Sa’ad 1967: 67; Austin and Ghazanfar 1979: 10; Petrov 1935: 133 (plate), Nowroozi 2002: 19 (plate), 100 (map); Breckle and Rafiqpoor 2010: 417 (photo)]

Notes.

Convolvulus leiocalycinus is the only spiny species in Central Asia with leaves abruptly narrowed at the base into a distinct petiole. Another unusual feature is the lax sepals which are not appressed to the base of the corolla. It is a variable species in many details but always with a common facies. Variety glaber was described on the basis of its glabrous leaves, Convolvulus olgae on its sericeous leaves and Convolvulus lycioides on its oblong leaves but the species, in fact, shows a wide range of leaf shape and indumentum with no obvious geographical patterning. We recognise two varieties.