1	"Calyces shallowly 5-lobed, completely enclosing the fruits"	"Heliotropium supinum"
1	"Calyces deeply divided into 5-lobed, not completely enclosing the fruits"	2
2	"Plants glabrous"	"Heliotropium curassavicum"
2	"Plants scabrous or with hairs"	3
3	"Stigmas 2, linear-recurved, exserted from the corolla tubes"	"Heliotropium ophioglossum"
3	"Stigmas solitary, minutely 2-fid or capitate, included in the corollas tubes"	4
4	"Stigmas capitate, entire"	"Heliotropium rariflorum"
4	"Stigmas conical, entire or not"	5
5	"At least some flowers subtended by bracts"	6
5	"All flowers without bracts"	8
6	"Plants semishrubby herbs; leaves linear, 25-50 mm long"	"Heliotropium zeylanicum"
6	"Plants prostrate to decumbent herbs; leaves linear lanceolate to elliptic"	7
7	"Inflorescences compact, 20-40 mm long; leaves lanceolate to elliptic; flowers sessile"	"Heliotropium marifolium"
7	"Inflorescences of well spaced flowers, 20-100 mm long; leaves linear lanceolate, at least lower down on the stems"	"Heliotropium strigosum"
8	"Corolla lobes caudate-acuminate"	"Heliotropium subulatum"
8	"Corolla lobes obtuse to ovate or caudate"	9
9	"Corollas hairy on the inner surface"	10
9	"Corollas glabrous on the inner surface"	15
10	"Hairs in the corollas in two disinct zones"	"Heliotropium baluchistanicum"
10	"Hairs not separated into different zones"	11
11	"Corollas 4-8 mm long"	12
11	"Corollas 2-3 mm long"	14
12	"Corolla lobes linear, inflexed; stigmas 1.5-1.8 mm long"	"Heliotropium gillianum"
12	"Corolla lobes more or less ovate, obtuse; stigmas 0.7-0.8 mm long"	13
13	"Leaves ovate-lanceolate to lanceolate; hairs with swollen bases; inflorescences with up to 9 flowers; corollas uniformly hairy within"	"Heliotropium cabulicum"
13	"Leaves ovate to ovate-oblong; hairs without swollen bases; inflorescences with up to 20 flowers; corollas not uniformly hairy within"	"Heliotropium biannulatum"
14	"Leaves ovate, 7-10 mm long; flowers well separated; anthers about 1 mm long, more or less ovate, attached about 0.9 mm from corolla bases; stigmas about 1 mm long"	"Heliotropium remotiflorum"
14	"Leaves elliptic to obovate, 10-25 mm long; flowers close together; anthers 0.5-0.6 mm long, narrow, attached about 0.5 mm from the corolla bases; stigmas about 0.4 mm long"	"Heliotropium ovalifolium"
15	"Plants annual"	16
15	"Plants perennial"	18
16	"Corolla lobes sublinear, inflexed"	"Heliotropium alii"
16	"Corolla lobes ovate to oblong, obtuse"	17
17	"Plants greyish white; flowers uniseriates; calyces eventually deciduous"	"Heliotropium calcareum"
17	"Plants green to greyish green; flowers biseriate; calyces persistent"	"Heliotropium europaeum"
18	"Corolla lobes ovate to oblong, obtuse"	19
18	"Corolla lobes sublinear, inflexed"	21
19	"Leaves ovate to oblong-ovate; anthers oblong, 1-8-2 mm long"	"Heliotropium ulophyllum"
19	"Leaves lanceolate to linear lanceolate; anthers narrowly ovate, 0.8-1 mm long"	20
20	"Plants decumbent to procumbent; stems up to 15 mm thick at the base; leaf margins revolute or indistinctly undulate; nutlet margins winged"	"Heliotropium bacciferum"
20	"Plants erect to suberect; stems up to 5 mm thick at the base; leaf margins crisp-undulate; nutlet margins not winged"	"Heliotropium crispum"
21	"Anther connectives not prolonged beyong the anthers"	"Heliotropium dasycarupum"
21	"Anther connectives prolonged beyond the anthers"	22
22	"Sinues of corolla lbes without teeth of lobes; anthers about 1 mm long"	"Heliotropium aucheri"
22	"Sinus of corolla lobes with teeth or lobes"	"Heliotropium lamondiae"