Ipomoea (Heine, 1963)

B. D., Williams, R. C., Francisco, B., Mewded, C. P., Oppong, C. B., Ayensu, C. W., Masinde, D. B., Chukwuma, A. G., Deresa, D. D., Yeboah, F., Rasaminirina, U. P., Igho-Osagie, M. J., Korir, K. B., Antwi-Boasiako, R. A., Mfodwo, A. S. M., Mutegeki, P., Atta-Adjei, P. K., Akomatey, S., Kumordzie, R., Borosova, C., Tang, A., Asase, G., Ameka & Simões, A. R. G., 2024, Advancing knowledge of West African morning glories: a taxonomic account of Ipomoea (Convolvulaceae) from Ghana, Rheedea 34 (5), pp. 397-429 : 402-404

Key to the species of Ipomoea in Ghana

1a. Stout shrub or tree; often carrying two glands at the base of the leaf ...................................... 2

1b. Climbing, suberect or prostrate herbs; without two glands at the base of the leaf........................ 3

2a. Trees; entire plant glabrescent or sparsely pilose; leaves lanceolate to narrowly ovate; corolla white or yellowish white, never with dark purple centre ........................ I. intrapilosa

2b. Stout shrub or subshrub; entire plant densely tomentose, with a mixture of whitish and yellowish trichomes; leaves broadly ovate to suborbicular; corolla pink or mauve, with dark purple centre.................................... I. verbascoidea

3a. Leaves deeply palmately 5–7-lobed............... 4

3b. Leaves entire, variable in shape, simple or shallowly 3-lobed............................................ 5

4a. Pair of stipules inserted at the base of the petiole; leaves palmately 5-lobed nearly to base, the outer lobes often lobulate, acutely mucronate; corolla 4.5 cm long, not contracted at the base.......................... I. cairica

4b. Leaves exstipulate; leaves usually 5–7-lobed to about the middle of the lamina, lobes acuminate; corolla c. 7 cm long, contracted at base................................................ I. mauritiana

5a. Plants stoloniferous; -leaves sub-succulent, often in aquatic environments, swamps or riverbanks; stems, floating, thick, fistulose or spongy............................................................. 6.

5b. Plant without stolon; -leaves not succulent; - stems not spongy or fistulose........................ 9

6a. Leaves narrowly to broadly triangular, linear-oblong, lanceolate or linear; corolla infundibuliform with a narrow tube, widening at the top, up to 8.5 cm long, purple, pink or white with a dark centre....................................... I. aquatica

6b. Leaves broadly orbicular or reniform; corolla broadly infundibuliform, up to 6.5 cm long, white, yellow, purple or red purple, with or without dark centre....................................... 7.

7a. Leaves broadly orbicular to reniform; apex obtuse to shortly acuminatE............... I. asarifolia

7b. Leaves reniform; apex emarginate to deeply bilobed ............................................................ 8.

8a. Corolla white or yellow, without dark centre; leaves reniform, apex rounded, base rounded ............................................................ I. imperati

8b. Corolla pink or red-purple with darker centre; leaves lanceolate, apex cuneate, base acute................................................ I. pes-caprae

9a. Inflorescences subsessile, many-flowered or sub solitary .................................................... 10

9b. Inflorescences distinctly pedunculate, few-flowered or solitary .....................................12

10a. Leaves entire, linear, lanceolate or narrowly oblong-lanceolate, plants glabrous or sparsely pilose ............................................................. 11

10b. Leaves entire to shallowly 3-lobed, ovate to linear-oblong in outline, plants densely pubescent with a mixture of whitish tomentose and yellowish hispid indumentum .... I. eriocarpa

11a. Leaves oblong-lanceolate; sepals c. 6 mm long; corolla 5–8 mm long, as long or slightly longer than the calyx, red or white .................................................. I. coscinosperma

11b.Leaves linear or oblong-linear; sepals 15–18 mm long; corolla up to 55 mm long, thrice as long as the calyx, mauve with dark purple centre ..................................... I. blepharophylla

12a. Inflorescences many-flowered, densely clustered heads; plants covered in whitish and yellowish indumentum; leaves pubescent....13

12b.Inflorescences 1–few-flowered, lax; plants glabrescent rarely pilose; leaves glabrous ....17.

13a. Bracteoles inconspicuous, up to 7 mm long .. .............................................................. I. aitonii

13b. Bracteoles large, up to 30 mm long............ 14

14a. Bracteoles subtending the inflorescence united into an oval involucre, 3–6 cm long ....................................................... I. involucrata

14b. Bracteoles subtending the inflorescence not united, 1.4–3 cm long................................... 15

15a. Plants erect; leaves oblong-lanceolate .................................................... I. argentaurata

15b. Plants twining; leaves ovate-subcordate ..........16.

16a. Peduncles 2–5 cm long; corolla 1.5–2 cm; sepals ± 9 mm; fruits ovoid........................ I. heterotricha

16b. ............. Peduncles 6–14 cm long; corolla 3.5– 5 cm; sepals 12–15 mm long; fruits globose ......................................................... I. delpierrei

17a. Sepals distinctly awned at or below the apex, awn straight or curved; corolla salver-shaped with a long and narrow tube; stamens and style mostly exserted ..................................................18

17b.Sepals not distinctly awned at or below the apex, obtuse, acute or acuminate, whether mucronulate or not; corolla mostly funnel-shaped, or campanulate, sometimes salver-shaped; stamens and style mostly included, sometimes exserted .................................... 20.

18a. Corolla scarlet, rarely pure white, 3–4.5 cm long; outer sepals 2–5 mm long (without awn), inner sepals 3–6 mm (without awn); leaves pinnately parted into numerous linear or filiform segments, rarely less deeply pinnately cut ................................................. 19

18b.Corolla white with greenish bands or pale bluish-purple, 5–15 cm long; outer sepals 5–12 mm long (without awn), inner sepals 7–15 mm (without awn) ..................17. I. alba

19a. Leaves deeply pinnately dissected, margin toothed ........................................... I. quamoclit

19b. Leaves entire, cordate to shallowly 3-lobed, margin entire to coarsely dentate .... I. hederifolia

20a. Leaves entire, oblong ovate, narrowly cordate, lanceolate or linear, apex mucronate rarely acute...................................... I. pyrophila

20b.Leaves entire or lobed, ovate, triangular or cordate, apex acuminate.............................. 21.

21a. Leaves covered with blackish dots on the lower surface; sepals imbricate, apex obtuse, glabrous .......................................... I. stenobasis

21b.Leaves without blackish dots on the lower surface; sepals not imbricate, apex acuminate, pilose .............................................................. 22

22a. Corolla salver-shaped, white and/or pale greenish-yellow with whitish-yellow centre. ............................................................ I. violacea

22b.Corolla funnel-shaped, mauve, violet to white with purple centre ....................................... 23.

23a. Corolla pubescent outside............................ 24

23b.Corolla completely glabrous........................ 25

24a. Corolla yellow, 1.5–2.5 cm long....... I. obscura

24b.Corolla purplish-red, pink, lilac or white, 4–5 cm long ................................................ I. rubens 25a. Ovary 4-locular; fruits 4-valved; corolla pink to mauve........................................................ 26

25b.Ovary 3-locular; fruits 3-valved; corolla blue, purple, mauve or magenta........................... 27

26a. Corolla 1.5–2.5 cm long; leaves sagittate, base auriculate-sagittate, apex acuminate .............................................................. I. triloba

26b.Corolla 3–5 cm long; leaves triangular to broadly ovate, base cordate, apex attenuate .............................................................. I. batatas

27a. Leaves ovate to circular, base auriculate, apex acuminate, pubescent; ....................... 27. I. nil

27b.Leaves ovate in outline, base cordate, apex rounded, glabrous................................. I. indica