Convolvulus angustissimus R.Br., Prodr. Fl. Nov. Holland 482. 1810. (Brown 1810: 482).

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 : 101-103

66. Convolvulus angustissimus R.Br., Prodr. Fl. Nov. Holland 482. 1810. (Brown 1810: 482). Figure 9, t. 37-43

Convolvulus geniculatus Lehm., Index Seminarum (HBG) 1826: 17. 1826. ( Lehmann 1826: 17). Type. None cited.

Convolvulus acaulis Choisy, Prodr. [A.P. de Candolle] 9: 406. 1845. ( Choisy 1845: 406). Type. SOUTH AUSTRALIA, Kangaroo Island, coll. not known (holotype P).

Convolvulus erubescens var. angustissimus (R.Br.) Choisy, Prodr. [A.P. de Candolle] 9: 412. 1845. ( Choisy 1845: 412). Type. Based on Convolvulus angustissimus R.Br.

Convolvulus adscendens de Vriese, Pl. Preiss 1: 346. 1845. ( Lehmann 1845: 346). Type. WESTERN AUSTRALIA, York District, Preiss 1924 (holotype LD; isotypes MEL 689918, MEL689919).

Convolvulus ascendens Walp., Repert. Bot. Syst. 6: 540. 1846, lapsus [spelling mistake] for Convolvulus adscendens de Vriese (1845). ( Walpers 1846: 540).

Convolvulus subpinnatifidus de Vriese, Pl. Preiss 1: 346. 1845. ( Lehmann 1845: 346). Type. AUSTRALIA, Beljarup, Hay, Preiss 1925 (holotype LD!; isotypes MEL689916, MEL689917).

Convolvulus erubescens var. fililobus Wawra, Itin. Princ. S. Coburgi 1: 102. 1883. ( Wawra 1883: 102). Type. AUSTRALIA, Victoria, Wawra 438. (holotype W!).

Convolvulus erubescens var. albus Guilf., Austral. Pl. Gard. 117. 1911. ( Guilfoyle 1911: 117). Type. AUSTRALIA, no type specified.

Convolvulus angustissimus subsp. fililobus (Wawra) R.W.Johnson, Austrobaileya 6: 30. 2001. ( Johnson 2001: 30). Type. Based on Convolvulus erubescens var. fililobus Wawra

Convolvulus angustissmus subsp. omnigracilis R.W.Johnson, Austrobaileya 6: 27. 2001. ( Johnson 2001: 27). Type. AUSTRALIA, Victoria, Forbes & Scarlett 1867 (holotype MEL; isotype BRI).

Convolvulus angustissimus subsp. peninsularum R.W.Johnson, Austrobaileya 6: 31. 2001. ( Johnson 2001: 31). Type. AUSTRALIA, South Australia, Alcock 4733 (holotype AD; isotype SYD).

Type.

AUSTRALIA, Tasmania, "Van Dieman’s Land near Risdon Cove" R. Brown s.n. [Bennett 2765] (lectotype BM!, portion on right side of sheet, designated here, isolectotype K!, also perhaps MEL).

Description.

Perennial herb with trailing or twining stems, pubescent to subglabrous to at least 40 cm but commonly short. Leaves extremely variable and often di/trimorphic on the same plant, petiolate, petioles 0.5-7 cm, diminishing in length upwards; lowermost leaves (if present) 1-2 × 0.3-1.5 cm, ovate-deltoid, obtuse, margin entire, undulate or sinuate-lobed especially towards the base, base cordate or truncate, the auricles poorly developed, entire to bi(tri-)fid; lower stem leaves 2-3 (-6) × 1.3-5 cm, broadly or narrowly ovate-deltoid in outline, entire undulate or deeply sinuate lobed, the basal auricle prominent, lobed with a short ascending lobe; upper stem leaves usually finely lobed, the central lobe linear-oblong, mostly 2.5-4.5 × 0.1-0.3 cm, acute or apiculate; auricles usually with a prominent ascending lobe resembling the terminal lobe but half its length together with short bifid reflexed lobes. Flowers pedunculate, axillary, usually solitary; peduncles 0.5-5 cm long, becoming recurved in fruit; bracteoles filiform, 1-2 mm long; pedicels 3-20 mm; sepals 4-7 × 2-2.5 mm, elliptic, rounded or acute, minutely mucronate, inner sepals slightly smaller; corolla 1.2-2 cm long, usually pink, weakly lobed, midpetaline bands pubescent only near apex; ovary glabrous; style glabrous, divided 3-10 mm above the base, stigmas 1-2 mm. Capsule glabrous; seeds 3-4 mm long, covered in low reticulate ridges. [ Johnson 2001: 23 -32, f. 7-8, map 7]

Distribution.

Principally southeastern Australia: Tasmania, Victoria, New South Wales, South Australia, Queensland, Western Australia (Milligan 90, Scarlett 83-395, Aston 2367, Hoogland 3078, Lea 1885, Coveny & Hind 11502, Jeanes 2084, Tilden 723, Coomber 2215, Gunn 721).

Notes.

Johnson’s (2001) division of this species into four subspecies is not satisfactory. In the first place the type subspecies is a plant whose leaves have entirely linear segments quite unlike the subsp. angustissimus illustrated by Johnson (2001: 28). There are in fact quite a lot of specimens which accord well with Robert Brown’s type collection including Wawra 438, the type of var. fililobus and Morrison 1445, Robertson 221, Constable 56058 and Burns 7. The second difficulty with Johnson’s infraspecific classification is that the majority of specimens we have seen are not accommodated satisfactorily in any one or other of his subspecies. Specimens which accord with a particular subspecies can be recognised but a large residue which fit none remains. In this account, therefore, Convolvulus angustissimus is treated as a single variable species without recognised subspecies, usually easily identified by its relatively large corolla, 1.2-2 cm long. However, specimens from Western Australia and South Australia have smaller corollas and seem to intergrade with Convolvulus remotus . Examples of specimens showing this introgression include Lea 26/9/1885, Andrews 657, Black 12, Koch 5/1898.