1	"Procumbent-decumbent annual herbs; leaves pinnatipartite or pinnatisect"	"Verbena supina"
1	"Erect or ascending perennial herbs; leaves variously incised or irregularly serrate-dentate"	2
2	"Plants with long creeping rhizomes; flowers large, with bracts much longer than calyx; peduncles and bracts not glandular; corolla tube 8–10 mm long; leaves very stiff and clasping stem"	"Verbena rigida"
2	"Plants with condensed rootstock; flowers small, with bracts shorter than to scarcely longer than calyx; leaves not stiff, narrowed at base and not clasping stem or if broad at base then more or less clasping stem"	3
3	"Leaves broad at base, stem-clasping"	4
3	"Leaves much narrowed towards base, not stem-clasping"	5
4	"Corolla-tube distinct, 3.5–5 mm long; bracts, calyx and peduncles distinctly glandular; bracts generally shorter than calyx; mericarps 1.5–1.8 mm long"	"Verbena bonariensis"
4	"Corolla-tube 2.5–3.5 mm long; bracts, calyx and peduncles only occasionally with a few stalked glands; bracts equal to or longer than calyx; mericarps 1.3–1.5 mm long"	"Verbena incompta"
5	"Leaves with lamina cuneate-attenuate, hence petiole absent or indistinct; peduncle and bracts abundantly glandular; bracts conspicuously longer than calyx; plants usually 0.5–0.8 m high"	"Verbena hispida"
5	"Leaves petiolate or at least lamina greatly narrowed basally; peduncle and bracts only ever sparsely glandular; bracts shorter than, equal or only slightly longer than calyx; plants mostly at least 1 m high"	6
6	"Flowers crowded, opening together in whorls"	7
6	"Flowers at first distant, opening singly along rachis"	10
7	"Plants usually up to 1 m high; inflorescence sparingly glandular (except peduncle, bracts and calyx strongly glandular), often lengthening at maturity to more than 200 mm long; peduncle hairy with hairs scattered, spreading and more or less appressed; leaves with more or less prominent lobes, especially basal leaves; corolla tube 2 – 2.5 mm long"	"Verbena litoralis"
7	"Plants usually 1–1.5 (–3) m high, not glandular"	8
8	"Plants sterile, no mature mericarps produced"	"Verbena x brasiliensis"
8	"Plants fertile, producing abundant mericarps at maturity"	9
9	"Inflorescences broad, somewhat corymbose, not or only slightly lengthening at maturity; peduncle with closely appressed hairs only; lamina narrowly ovate, with margin toothed; lower leaves with teeth somewhat rounded; corolla tube 2 – 2.5 mm long"	"Verbena caracasana"
9	"Inflorescences narrow, often appearing fastigiated; peduncle densely covered with spreading hairs; lamina narrowly ovate, with margin toothed, especially in the distal half, sometimes with deeper incisions at margin; corolla tube 3 – 3.5 mm long"	"Verbena quadrangularis"
10	"Inflorescences lacking glands; hairs inconspicuous; leaves often deeply incised, such that lamina reduced to a central narrow rachis with long narrow, obtuse lobes"	"Verbena gaudichaudii"
10	"Inflorescences, bracts and calyces distinctly glandular; hairs distinct or inconspicuous; leaves variously serrate but lamina not reduced to a central rachis"	11
11	"Plants strongly hispid; leaves densely hairy (hairs often 1 mm long), with distal lamina usually not deeply pinnatifid; infructescences with long, thick, densely arranged axes"	"Verbena macrostachya"
11	"Plants much less hispid; leaves shortly hairy (hairs 0.2 – 0.5 mm long), with distal lamina 1- or 2-pinnatifid; infructescences long and thin"	12
12	"Leaves bluntly serrate; basal leaves lobed, like those of an English Oak; bracts shorter than calyx"	"Verbena officinalis"
12	"Leaves sharply serrate; basal leaves variously divided, never ‘oak-like’ or pinnatifid; bracts at least as long as calyx"	"Verbena africana"