Common Name: Verbenas
Description: Herbs, sometimes slightly woody at base, open or even decumbent, matted or tufted, rarely glabrous.
Leaves mostly decussate, rarely whorled, margin entire or variously incised to pinnatisect.
Inflorescences terminal or rarely axillary, elongated to capitate spikes, usually dense, many-flowered, often elongating after flowering; flowers solitary in axil of bracts. Calyx usually tubular, unequally and minutely 4- or 5-toothed. Corolla tube straight or slightly curved; lobes 5, slightly unequal and spreading. Stamens 4, didynamous, included in corolla tube. Ovary 4-locular with 1 ovule per loculus.
Fruit dry, separating at maturity into 4, 1-seeded mericarps.
Distribution and occurrence: World: c. 250 species, mainly temperate, subtropical & tropical America and the Near East region, widely cultivated;; 2 species from Mediterranean region. Australia: c. 13 species (c. 10 species naturalized), Qld, N.S.W., Vic., Tas., S.A.
Text by B.J. Conn
Taxon concept: B.J. Conn (1999)
| | Key to the species | |
| 1 | Leaves with base of lamina subcordate, slightly clasping branch, hence lamina distinctly sessile; margin variously serrate, never lobed | 2 |
| Leaves with base of lamina acute, attenuate, tapering or narrow; lamina shortly petiolate or superficially appearing so, but never clasping branch; margin variously pinnatifid, or at least with some leaves variously toothed or sometimes with margin of some leaves entire | 4 |
| 2 | Bracts conspicuously longer than calyx; corolla-tube c. 3 times longer than calyx | Verbena rigida |
| Bracts shorter than, equal to or slightly longer than calyx; corolla-tube up to 2 times longer than calyx
Back to 1 | 3 |
| 3 | Corolla-tube distinct, much longer than calyx; bracts, calyx and peduncles distinctly glandular; mericarps 1.5–1.8 mm long | Verbena bonariensis |
| Corolla-tube only slightly longer than calyx; bracts, calyx and peduncles only occasionally with a few stalked glands; mericarps 1.3–1.5 mm long
Back to 2 | Verbena incompta |
| 4 | Lower leaves with margin variously pinnatifid or pinnatisect; ultimate divisions narrowly linear, or subulate to narrowly obovate (note: upper leaves smaller, with margin incised to subentire) | 5 |
| 4 | Leaves (upper and lower) with margin variously toothed or sometimes with margin of some leaves entire, never pinnatifid or pinnatisect; ultimate divisions more or less obliquely ovate to triangular | 6 |
| 5 | Calyx 5-toothed, long-tubular, 6–9 mm long; corolla tube 11–14 mm long; spike with flowers overlapping each other | Glandularia aristigera |
| Calyx 4-toothed, to c. 3 mm long; corolla tube 1.5–2 mm long; spike with flowers not or just overlapping each other
Back to 4 | Verbena supina |
| 6 | Branches moderately glandular distally | 7 |
| Branches non-glandular
Back to 4 | 8 |
| 7 | Branches with eglandular hairs antrorse; calyx 5-toothed; infloresnce spikes compact, 6–12 mm diameter | Verbena hispida |
| Branches with eglandular hairs variously spreading; calyx 4-toothed; inflorescence slender, 5–6 mm diameter
Back to 6 | Verbena macrostachya |
| 8 | Calyx 4-toothed; branches glabrous, except for a few hairs on or near nodes | Verbena caracasana |
| Calyx 5-toothed; branches variously hairy throughout, may be sparsely so, or glabrous
Back to 6 | 9 |
| 9 | Flowers crowded, opening together in whorls | Verbena quadrangularis |
| Flowers distant, opening singly along inflorescence axis
Back to 8 | 10 |
| 10 | Leaves deeply incised, such that lamina reduced to a central narrow rachis with long, narrow lobes (teeth); inflorescence lacking glands | Verbena gaudichaudii |
| Leaves variously serrate, but lamina not reduced to a central rachis; inflorescences glandular or eglandular (V. x brasiliensis and V. litoralis)
Back to 9 | 11 |
| 11 | Inflorescences eglandular | 12 |
| Inflorescences, bracts and calyces distinctly glandular
Back to 10 | 13 |
| 12 | Inflorescences consisting of long slender spikes, with flowers spaced along axis, flowers opening together in a narrow zone near apex of inflorescence; lower leaves variously acutely serrate, 1- or 2-pinnatifid | Verbena litoralis |
| Inflorescences consisting of long slender spikes, with flowers crowded together, flowers opening together in distal part of inflorescences, but in a broader zone than for V. litoralis; lower leaves coarsely serrate, never pinnatifid
Back to 11 | Verbena x brasiliensis |
| 13 | Leaves with margin bluntly serrate, 1- or 2-pinnatifid; corolla twice as long as calyx; bracts shorter than calyx | Verbena officinalis |
| Leaves with margin serrate, never pinnatifid; corolla slightly longer than calyx; bracts at least reaching top of calyx or shorter than calyx
Back to 11 | Verbena africana |
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