These are the keys from Flora of Pakistan:
18 (17) Sepals semi-membranous, glabrous 18
Convolvulus stocksii+
Sepals tomentose to pilose, not membranous (19) 19 (18) Flowers 4-10, bracts 12 mm long, ovate. Stigma cylindrical. Leaves sub-petiolate, the upper auriculate, lower attenuate 16
Convolvulus glomeratus+Flowers 1-3, bracts 5-8 mm long, lanceolate to oblanceolate. Stigma filiform. Leaves sessile, attenuate
(20) 20 (19) Inner sepals ovate to ovate-lanceolate, acuminate. Style as long as the stigma 14
Convolvulus pilosellifolius+Inner sepals obovate, caudate. Style 1.5-2 times the length of stigma 17
Convolvulus rottlerianus
Close up details of flowers and sepals will help in deciding the species among these two. Pl. send.
From perusal of specimens at POWO, it appears more closer to
Convolvulus rottlerianus subsp.
stocksii (Boiss.) J.R.I.Wood & Scotland (
POWO specimen) than
Convolvulus rottlerianus subsp.
rottlerianus (
POWO specimen).