Description: Annual or perennial herbs or shrubs usually with trailing or twining stems, rarely erect.
Leaves simple [or rarely compound], margins entire to deeply lobed, glabrous or with simple hairs, occasionally with pseudo-stipules.
Inflorescence axillary, 1–many-flowered cymes, bracteolate. Sepals 5, free, usually unequal and overlapping. Corolla funnel-shaped, campanulate or rarely trumpet-shaped, entire or slightly 5-lobed with distinct glabrous or hairy mid-petaline bands. Stamens 5, usually ± unequal, hairy above the point of attachment. Ovary 2–4-locular with 2 ovules per loculus, glabrous [or rarely pilose]; style 1, stigma capitate or biglobose.
Capsule globose or ovoid, usually splitting longitudinally into 4–6 valves, rarely indehiscent.
Distribution and occurrence: World: c. 500 species, tropical to warm-temp. regions. Australia: c. 50 species (20 species endemic, 12 species naturalized), all States.
I. batatas (L.) Lam., the Sweet Potato, is cultivated for its edible tubers and sometimes persists around old gardens and rubbish tips.
Text by R. W. Johnson. Key modified by P.G. Wilson and K.L. Gibbons, Aug. 2022 Taxon concept:
| Key to the species | |
1 | Sepals awned at or below the apex; corolla trumpet-shaped | 2 |
| Sepals not distinctly awned, corolla funnel-shaped or campanulate | 4 |
2 | Leaves pinnately divided into linear lobes; corolla red | Ipomoea quamoclit |
| Leaves with margins entire or shallowly lobed Back to 1 | 3 |
3 | Corolla red, less than 5 cm long | Ipomoea hederifolia |
| Corolla white, more than 5 cm long Back to 2 | Ipomoea alba |
4 | Leaves palmately divided to the base | Ipomoea cairica |
| Leaves entire or lobed Back to 1 | 5 |
5 | Corolla white | 6 |
| Corolla pink to reddish-purple Back to 4 | 8 |
6 | Sepals and corolla glabrous; stems coarse, trailing | Ipomoea diamantinensis |
| Sepals ciliate; mid-petaline band hairy; stems trailing or twining Back to 5 | 7 |
7 | Stems twining; leaves cordate | Ipomoea plebeia |
| Stems trailing; leaves attenuate or rounded at the base Back to 6 | Ipomoea lonchophylla |
8 | Erect or decumbent herb | Ipomoea polymorpha |
| Trailing or twining herb Back to 5 | 9 |
9 | Stems trailing; leaves more or less leathery, rounded, emarginate | Ipomoea brasiliensis |
| Stems twining; leaves herbaceous, ovate, acuminate Back to 8 | 10 |
10 | Leaf base hastate | Ipomoea fimbriosepala |
| Leaf base rounded to cordate Back to 9 | 11 |
11 | Plants pilose with yellowish hairs; leaves strongly discolorous | Ipomoea wightii |
| Plants not as above Back to 10 | 12 |
12 | Sepals acute, less than 15 mm long; inflorescence 1- to few-flowered, bracteoles less than 7 mm long | Ipomoea purpurea |
| Sepals long attenuate, more than 15 mm long; inflorescence many-flowered, bracteoles more than 1 cm long Back to 11 | Ipomoea indica |
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