1	Corolla salverform, the long narrow tube only slightly wider near or above the middle, abruptly flaring near the summit. Anthers exserted. Flowers opening during night and closing in early morning (white or lavender scarlet flowers) or open most of the day (red or scarlet flowers)		(2)
+	Corolla funnel-shaped to campanulate, the short to long tube expanding from below the middle, gradually or abruptly flaring near the summit. Anthers mostly included. Open during morning, closing near noon		(6)
2 (1)	Corolla 2-5 cm long, red to orange or yellowish (rarely white). Flowers open during most of day		(3)
+	Corolla 6-16 cm long, the limb or tube white or lavender. Flowers opening during night and closing in early morning		(5)
3 (2)	Leaf blades divided more than halfway to the midrib and appearing pinnately compound, the segments linear		15 Ipomoea quamoclit
+	Leaf blades divided less than halfway to the mid-rib, appearing pinnately or palmately lobed, the segments mostly lanceolate		(4)
4 (3)	Sepals 5-8 mm long		16 Ipomoea x multifida
+	Sepals 1.5-3 mm long		8 Ipomoea hederifolia
5 (2)	Flower tube 9-15 mm long. Fruit 2-3 cm long		1 Ipomoea alba
+	Flower tube 3-6 mm long. Fruit 1.8-2 cm long		18 Ipomoea turbinata
6 (1)	Glabrous perennials with procumbent stems, not normally twining. Leaves fleshy or leathery. Se-pals elliptic-oblong to orbicular. Habitat of coastal dunes and beaches or inland waterway margins or cultivated wetlands		(7)
+	Glabrous or pubescent annuals or perennials with twining or erect stems, not usually rooting at the nodes (except in I. batatas). Leaves chartaceous to fleshy. Sepals acuminate to suborbicular. Habitat various		(8)
7 (6)	Flowers white, with light or dark throat inside tube. Leaves sagittate		2 Ipomoea aquatica
+	Flowers pink, lavender or purple. Leaves sub-orbicular to suborbicular-oblong, apically emarginate		12 Ipomoea pes-caprae
8 (6)	Sepals herbaceous. Sepals, peduncles and pedi-cels with reflexed or erect trichomes (except I. indica). Stigmas with 3 lobes (rarely 2), ovary 3-4-locular (rarely 2-locular). Corolla blue, red or white or inflorescence sub-capitate or bracteate		(9)
+	Sepals coriaceous or membranaceous, rarely herbaceous. Sepals, peduncles and pedicels glabrous or at least without reflexed trichomes. Stigmas with 2 lobes, ovary 2-locular. Corolla mostly lavender, sometimes blue or white, the inflorescences rarely bracteate		(14)
9 (8)	Corolla 5-7 cm long. Sepals soft-pubescent out side with slender trichomes or rarely glabrous		10 Ipomoea indica
+	Corolla mostly less than 5 cm long. Sepals hispid pilose outside with long spreading trichomes		(10)
10 (9)	Leaves deeply palmately 7-9-lobed, the lobes cut almost to the blade base		13 Ipomoea pes-tigridis
+	Leaves entire, toothed or shallowly 3-lobed, the lobes cut less than halfway to the blade base		(11)
11 (10)	Flowers in sub-capitate to capitate inflorescences, occasionally involucrate or bracteate. Corolla 0.7-3 cm long		7 Ipomoea eriocarpa
+	Flowers solitary or in open cymose inflorescences. Corolla 4-8 cm long		(12)
12 (11)	Sepals with slightly narrowed green tips, shorter to slightly longer than the body		14 Ipomoea purpurea
+	Sepals with very narrow elongate green tips, much longer than the body		(13)
13 (12)	Sepal tips erect or slightly curved		11 Ipomoea nil
+	Sepal tips curved to one side, at least when plants are in fruit		9 Ipomoea hederacea
14 (8)	Shrubs, woody. Seeds comose, atleast on margins		6 Ipomoea cornea ssp. fistulosa
+	Climbers, herbaceous. Seeds glabrous or densely shortly pubescent		(15)
15 (14)	Leaves densely white-cottony pubescent below. Corolla 1.2-1.7(-2) cm long		3 Ipomoea arachnosperma
+	Leaves glabrous to very sparsely pubescent below. Corolla mostly over 3 cm long		(16)
16 (15)	Leaves palmately divided to the base. Pseudo-stipules present		5 Ipomoea cairica
+	Leaves entire or lobed but not palmately divided to the base. Pseudo-stipules absent		(17)
17 (16)	Margins of sepals scarious. Flowers blue		17 Ipomoea tricolor
+	Margins of sepals not obviously scarious. Flowers lavender		4 Ipomoea batatas