Convolvulus rectangularis Rech.f., Biol. Skr. 10(3): 81. 1959. (Rechinger 1959: 81).

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 : 108

75. Convolvulus rectangularis Rech.f., Biol. Skr. 10(3): 81. 1959. (Rechinger 1959: 81).

Type.

AFGHANISTAN, Volk 1018 (holotype W!).

Description.

Perennial herb with woody rootstock from which arise many wiry, probably scrambling stems to at least 25 cm; stems striate, glabrescent. Leaves very shortly petiolate, 1-3.5 × 0.4-0.6 cm, lanceolate-deltoid, acute, margin entire to sinuate-lobed, base truncate to auriculate, shortly crisped pubescent when young, glabrescent; petioles 1-3 mm. Flowers 1-3, borne on axillary peduncles; peduncles 1-1.5 cm; bracteoles 2.5 mm, filiform; pedicels 4-10 mm; outer sepals 9-10 × 6 mm, broadly oblong-rectangular, truncate and minutely mucronate, margin scarious, purplish, pubescent and with ciliate margins, inner sepals oblong, c. 4 mm wide; corolla 2.3-3.2 cm long, pinkish, midpetaline bands pubescent; filaments glandular below; ovary glabrous, style glabrous, divided c. 7 mm above base; stigmas not seen. Capsule glabrous; seeds wrinkled. [ Sa’ad 1967: 104; Rechinger 1963: 17]

Distribution.

Afghanistan (Rechinger 35902, 37103).

Notes.

Although placed as distantly related in different sections by Sa’ad, Convolvulus rectangularis and Convolvulus lanjowii are quite close and might prove to be conspecific. The description above is based on the two widely distributed Rechinger collections cited above. These differ clearly in their sparse indumentum and in the sinuate-lobed narrower leaves with a rather rigid texture from Convolvulus lanjouwii . However the type and Amsel s.n. (W) are much more hirsute and with unlobed leaves so approaching Convolvulus lanjouwii . Further collections are needed to confirm whether two distinct species are really involved.