Ipomoea L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 82

6. Ipomoea L. 1

(incl. Pharbitis Choisy )

Annual or perennial herbs with long, trailing or climbing stems. Leaves entire or lobed, alternate; petioles long, distinct. Flowers solitary or in axillary cymes, usually with 2 very small bracteoles. Corolla at least 25 mm, infundibuliform or tubiform, scarcely lobed, more or less glabrous. Ovary 2- to 4-locular; ovules usually 2 in each loculus; style filiform; stigma with 1-3 globose lobes. Capsule usually 4-seeded. Pollen grains pantoporate; exine spinose. The leaves in all species may vary considerably in shape, usually being entire near the base of the plant and variously lobed towards the apex. The descriptions cover most of this variation, but ignore the lowest leaves which are often very aberrant.

3 and 4 are two of several species grown for ornament and frequently found as casuals over much of Europe; they have been very much confused in the past.

1 Sepals acute to rounded, usually abruptly mucronate, glabrous or rarely hairy

2 Leaves sagittate 2. sagittata

2 Leaves not sagittate

3 Plant without underground tubers; leaves obtuse to emarginate or 2-lobed at apex 1. stolonifera

3 Plant with large underground tubers; leaves acute to acuminate at apex or at apex of lobes 5. batatas

1 Sepals acute to long-acuminate, pubescent

4 Sepals finely pubescent, without bristles 3. acuminata

4 Sepals finely pubescent and also with long bristles near the base 4. purpurea