Convolvulus rhyniospermus Hochst. ex Choisy, Prodr. [A.P. de Candolle] 9: 405. (Choisy 1845: 405).

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 : 122-123

93. Convolvulus rhyniospermus Hochst. ex Choisy, Prodr. [A.P. de Candolle] 9: 405. (Choisy 1845: 405). Figure 13, t. 18-25.

Convolvulus hamphilahensis Terracc., Ann. Inst. Bot. Roma 5: 105. 1894. ( Terracciano 1894: 105). Type. ERITREA, Terracciano 148 (holotype FT).

Convolvulus densiflorus Blatt. & Hallb., J. Bombay Nat. Hist. Soc. 26: 545. 1919, nom. illeg., non Convolvulus densiflorus Hook. & Arn. (1827). ( Blatter and Hallberg 1919: 545). Type. INDIA, Blatter 3515 (lectotype BLATT!, designated by Bhandari 1964: 327).

Convolvulus blatteri Bhandari, Bull. Bot. Surv. India 6: 327. 1964. ( Bhandari 1964: 327). Type. Based on Convolvulus densiflorus Blatt. & Hallb.

Convolvulus rhyniospermus var. leavis Sa’ad, Meded. Bot. Mus. Herb. Rijks Univ. Utrecht 281: 195.1967. ( Sa’ad 1967: 195). Type. SAUDI ARABIA, Jiddah, Kruijt 191 (holotype L).

Type.

SUDAN, Kordofan [Kurdufan], Kotschy 235 (holotype G; isotypes BM001050391!, K!, OXF!, P!).

Description.

Annual herb, often branched at base, pubescent in all vegetative parts, stems prostrate to ascending, up to 60 cm long. Leaves shortly petiolate, 0.5-4.5 × 0.1-1.3 cm. ovate, lanceolate, elliptic or oblanceolate, obtuse or acute, margin entire, base cuneate, rarely truncate; petioles 2 mm long. Flowers 3-6 in subsessile, axillary, bracteate heads; peduncles 0-0.5(-3) cm long; bracteoles 4-8 × 2-3 mm, lanceolate or ovate; outer sepals 4-7 × 0.5-1.5 mm, lanceolate, acute, densely villous; corolla 4-5 mm long, white or pale pink, deeply lobed, the lobes longer than broad, 2-2.5 mm long, more or less hidden by calyx hairs, midpetaline bands glabrous, ovary glabrous; style glabrous, divided 2-2.5 mm above base, stigmas c. 1.5 mm long; capsule glabrous, seeds tuberculate or ( var. laevis Sa’ad) smooth. [ Sa’ad 1967: 194; Collenette 1999: 231 (photo); Thulin 2006: 235; Austin and Ghazanfur 1979: 27, 25 (plate)]

Distribution.

A Saharo-Sindian species, unexpectedly absent from southern Arabia and the Gulf region: India (Aggarwal s.n. [12/1/1955]); Pakistan (Stocks 474, Jafri 816); Saudi Arabia (Collenette 4734, Trott 1338); Egypt (Khattab 6346); Sudan (MacDougal & Sykes 36); Chad (Gaston 568); Ethiopia: Bale/Barrei (Rippstein 1236); Eritrea (Popov 1396); Djibouti (Collenette 8679, Audru 7117); Somalia (Bally 10218, Thulin et al. 9233); Yemen, Hadramaut (Monod 16530, 17334); Socotra (Popov SO/98).

Notes.

The glabrous midpetaline bands of this, the previous and the following species are unusual.

Convolvulus blatteri was distinguished by its very small pale pink corolla, precisely the distinguishing character for Convolvulus rhyniospermus and images of the type kindly sent by the Blatter herbarium (BLATT) do not suggest any other differences. According to Bhandari his Convolvulus rhyniospermus has pedunculate brownish-villous heads with a corolla 16 mm. This fits Convolvulus glomeratus , known from Sind adjacent to the Jodhpur region and it seems likely that Convolvulus blatteri was described as a consequence of confusion with Convolvulus glomeratus , which was treated under the name Convolvulus auricomus by Bhandari. Convolvulus hamphilahensis was distinguished by the corolla being shallowly lobed with lobes broader than long, 0.5-1 mm in length but this does not justify specific or subspecific rank in the absence of other distinguishing morphological or ecological features.