1	Sepals distinctly awned at or below apex; corolla salverform with a long narrow tube; stamens and pistil mostly exserted.		(2)
+	Sepals rounded to acuminate, emarginate, or mucronulate but never awned at or near apex; corolla mostly funnelform, or campanulate, sometimes salverform; stamens and pistil mostly included, sometimes exserted.		(6)
2 (1)	Corolla longer than 4.5 cm, white or purplish; outer sepals 5-12 mm (excluding awn), inner sepals 7-15 mm (excluding awn).		(3)
+	Corolla 3-4.5 cm, scarlet, rarely pure white; outer sepals 2-4.5 mm (excluding awn), inner sepals 3-6 mm (excluding awn).		(4)
3 (2)	Corolla white, tube slightly widened apically or not, 7-12 cm; stamens and style exserted		21 Ipomoea alba
+	Corolla purplish, tube distinctly widened apically, 3-6 cm; stamens and style scarcely exserted or not		22 Ipomoea turbinata
4 (4)	Leaves cordate, entire, angled, or palmately lobed, not pinnately parted I.hederifolia		(4)
+	Leaves linear-lanceolate, linear, or filiform, pinnately parted.		(5)
5 (5)	Leaf segments ca. 3-7 on either side of midvein, linear or linear-lanceolate I.sloteri		(5)
+	Leaf segments more numerous, linear or filiform I. quamoclit		(1)
6 (1)	Corolla ca. 10 cm or longer, salverform with a long and narrow tube, white or with greenish midpetaline bands; seeds long pubescent at least on margin; plants large twiners.		(7)
+	Corolla usually less than 10 cm, funnelform or campanulate, rarely salverform and then not longer than ca. 7 cm; seeds pubescent or glabrous; plants large to small twiners, or prostrate or erect.		(8)
7 (6)	Stamens inserted near mouth of corolla tube; sepals subequal or outer sepals slightly longer than inner sepals		29 Ipomoea aculeata var. mollissima
+	Stamens inserted near base of corolla tube; sepals equal or outer 2 shorter than inner ones		28 Ipomoea violacea
8 (6)	Sepals hairy abaxially or with fimbriate or ciliate margin.		(9)
+	Sepals glabrous, sometimes muricate or dentate on veins.		(23)
9 (8)	Peduncles very short ( < 1.5 cm) or absent; corolla to 1.9 cm.		(10)
+	Peduncles mostly longer, well developed; corolla mostly longer than 2 cm.		(12)
10 (9)	Herbs erect to decumbent; leaf blade cuneate and attenuate basally		4 Ipomoea polymorpha
+	Herbs twining or prostrate; leaf blade cordate basally.		(11)
11 (10)	Ovary and capsule pubescent; pedicel absent or very short, to 3 mm; outer sepals linear-acuminate from an ovate base; corolla pink or purplish, 7-9 mm		1 Ipomoea eriocarpa
+	Ovary and capsule glabrous; pedicel 8-15 mm; outer 3 sepals deltate-lanceolate, base auriculate; corolla white, 12-19 mm		2 Ipomoea biflora
12 (9)	Flowers clustered at peduncle apex (capitate), subtended by 1 or more involucrate bracts.		(13)
+	Flowers clustered at apex of peduncle or not, not distinctly involucrate.		(14)
13 (12)	Leaves palmately divided nearly to base; bracts oblong; outer sepals lanceolate, apex acute; corolla funnelform, white		9 Ipomoea pes-tigridis
+	Leaves entire; bracts navicular; outer sepals elliptic-spatulate, apex obtuse; corolla salverform, pink or purple		10 Ipomoea pileata
14 (12)	Sepals 4-5 mm or less		14 Ipomoea obscura
+	Sepals ca. 5 mm or longer.		(15)
15 (14)	Erect shrubs or scandent subshrubs; sepals elliptic or ovate to circular, apex rounded, obtuse, or emarginate.		(16)
+	Twiners or prostrate; sepals narrower, apex usually acute or acuminate, rarely obtuse.		(17)
16 (15)	Sepals 13-15 mm, apex obtuse or emarginate; corolla 5.5-6.5 cm; scandent subshrubs; leaves ovate-cordate, lateral veins ca. 14 pairs		26 Ipomoea soluta var. alba
+	Sepals 5-6 mm, apex rounded; corolla 7-9 cm; erect shrubs; leaves ovate or ovate-oblong, lateral veins 7-9 pairs		27 Ipomoea carnea subsp. fistulosa
17 (15)	Sepals long attenuate, or long and linear-acuminate apically, herbaceous; corolla bluish aging to pinkish.		(18)
+	Sepals acute, acuminate, or obtuse apically, mucronulate or not, not long attenuate, herbaceous, membranous, or leathery; corolla reddish, purplish, lilac to pink, or white.		(19)
18 (17)	Outer sepals lanceolate basally, with a long linear acumen, spreading hirsute basally		7 Ipomoea nil
+	Outer sepals lanceolate to broadly lanceolate basally, long and gradually attenuate apically, appressed hairy		8 Ipomoea indica
19 (17)	Outer sepals 5-10 mm, mucronulate, glabrous to pilose abaxially, margin ciliate or fimbriate; corolla 1.5-4 cm.		(20)
+	Outer sepals 10-16 mm, not mucronulate, purplish bristly or hirsute abaxially, margin neither ciliate nor fimbriate; corolla 5-7 cm.		(21)
20 (19)	Plants with subterranean tubers; stems mostly prostrate, rarely twining, rooting at nodes, thick		11 Ipomoea batatas
+	Plants without tubers; stems mostly twining, thinner		12 Ipomoea triloba
21 (19)	Plants ± purplish or blackish bristly on stems, petioles, inflorescences, and abaxial side of sepals; leaves deeply 3-7-lobed, lobe margin undulate-serrate		23 Ipomoea setosa
+	Plants ± hirsute; leaves entire or shallowly 3-lobed, lobe margin entire.		(22)
22 (21)	Plants densely yellowish hirsute; stamens less than 6 mm, filaments glabrous basally; ovary 2-loculed; stigma 2-lobed		5 Ipomoea hirtifolia
+	Plants short pubescent mixed with longer retrorse hirsute hairs; stamens unequal, longest stamens reaching middle of corolla tube, filaments pubescent basally; ovary 3-loculed; stigma 3-lobed		6 Ipomoea purpurea
23 (8)	Outer sepals with 3 dentate keels		3 Ipomoea fimbriosepala
+	Outer sepals not keeled or dentate.		(24)
24 (23)	Sepals ca. 1.4 cm or longer.		(25)
+	Sepals less than 1.4 cm.		(26)
25 (24)	Sepals subequal, gradually linear-acuminate apically		8 Ipomoea indica
+	Sepals unequal, outer sepals rounded-obtuse apically, inner sepals acute apically		20 Ipomoea wangii
26 (24)	Leaves palmately lobed to palmately compound.		(27)
+	Leaves not palmately divided.		(31)
27 (26)	Leaves palmately parted to base; pseudostipules (small leaves of axillary shoot) often present		19 Ipomoea cairica
+	Leaves palmately lobed to or mostly below middle, but not to base; pseudo-stipules absent.		(28)
28 (27)	Stems twining; sepals rounded or obtuse apically, not mucronulate.		(29)
+	Stems prostrate, rooting at nodes; inner sepals oblong to elliptic-oblong, distinctly mucronulate.		(30)
29 (28)	Sepals ± equal or outer 2 shorter, ± circular, broadly elliptic, occasionally oblong, concave; corolla funnelform		24 Ipomoea mauritiana
+	Sepals unequal, outer 2 longer, ovate to oblong, ± flat; corolla ± salverform		23 Ipomoea setosa
30 (28)	Leaves herbaceous, thin, middle lobe acute or subacute; corolla pink, purple, or white; subterranean tubers present; plants cultivated, occasionally escaping		11 Ipomoea batatas
+	Leaves fleshy, middle lobe obtuse or emarginate; corolla white with a pale yellow tube and a dark red center; without subterranean tubers; plants of sandy seashores		18 Ipomoea imperati
31 (26)	Plants large, woody, glabrous twiners; flowers in axillary panicles, fundamental units cymose		25 Ipomoea sumatrana
+	Plants smaller, mostly herbaceous twiners, or prostrate plants, glabrous or pubescent; flowers in few- to several-flowered axillary cymes, or solitary in leaf axils.		(32)
32 (31)	Corolla ± salverform		16 Ipomoea marginata
+	Corolla funnelform to campanulate.		(33)
33 (32)	Corolla to 2.5 cm		14 Ipomoea obscura
+	Corolla ca. 3 cm or longer.		(34)
34 (33)	Plants of marshy places or aquatic, often cultivated for food (stems and leaves eaten); stems usually repent and rooting, or floating, thick, fistulose		15 Ipomoea aquatica
+	Plants terrestrial; stems twining or repent.		(35)
35 (34)	Stems mostly (or at least partly) twining.		(36)
+	Stems prostrate or trailing, mostly rooting at nodes, rarely twining, usually thick.		(37)
36 (35)	Sepals distinctly mucronulate, outer concave; corolla pink or pink-purple, with a darker center		13 Ipomoea littoralis
+	Sepals without a mucro, outer flat; corolla blue, with a paler or white center I. tricolor		(35)
37 (35)	Leaves herbaceous, attenuate toward acute or obtuse apex; plants with subterranean tubers, cultivated for edible tubers		11 Ipomoea batatas
+	Leaves ± leathery or fleshy, apex mostly obtuse to broadly rounded, or emarginate; plants without subterranean tubers.		(38)
38 (37)	Corolla white or yellowish, with a dark red center; leaves linear, lanceolate, oblong, or ovate (often on the same plant), apex obtuse or emarginate		18 Ipomoea imperati
+	Corolla purple or reddish purple; leaves ± reniform, circular, elliptic, ovate or quadrangular to oblong, apex deeply 2-lobed or emarginate		17 Ipomoea pes-caprae