Plectranthus L'Her ., Stirp. Nov.: 84, verso 1788

Paton, Alan J., Mwanyambo, Montfort, Govaerts, Rafael H. A., Smitha, Kokkaraniyil, Suddee, Somran, Phillipson, Peter B., Wilson, Trevor C., Forster, Paul I. & Culham, Alastair, 2019, Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera, PhytoKeys 129, pp. 1-158 : 110

Plectranthus L'Her., Stirp. Nov.: 84, verso 1788 nom. cons. Figs 8 , 9

Germanea Lam., Encycl. 2: 690. 1788. Lectotype species: G. urticifolia Lam. (here placed under Plectranthus fruticosus L’Hér.) designated by Heath (2001).

Lectotype species.

Plectranthus fruticosus L’ Hér. (typ. cons.).

Description.

Perennial, rarely annual herbs or soft-wooded shrubs, sometimes succulent; sometimes with a tuberous base. Leaves opposite. Inflorescence thrysoid, usually lax; cymes sessile, 1-3-flowered; bracts subtending cymes persistent. Flowers pedicelate. Calyx funnel-shaped straight, with pedicel attaching symmetrically at calyx base, not opposite posterior lip, two-lipped; throat glabrous within, open; posterior lip 1-lobed, broader than lobes of anterior lip, shortly decurrent on tube or not; anterior lip 4-lobed; lobes lanceolate; lateral lobes broader at base than medial lobes and held closer to the median lobes than the posterior lip; median lobes usually fused for a greater distance than the lateral and median lobe. Corolla two-lipped with lips equal in length; tube straight or gently curved downwards, often gibbous, saccate or almost spurred a base, more rarely dilating gradually towards throat; posterior lip 4-lobed erect, often becoming reflexed; anterior lip cucullate or concave straight or becoming reflexed. Stamens 4, very rarely only 2 fertile ( P. zuluensis ); filaments not fused together (anterior stamen and adjacent posterior stamen sometimes fused in P. alboviolaceus ), held within the anterior lip or becoming free from it and sometimes coiling downwards away from style after anthesis. Style bifid with lobes subulate. Nutlets ovoid.

72 species in Southern and Tropical Africa and Madagascar and including one in Sri Lanka.

Figures

Figure 8. Species of Plectranthus 1. A Plectranthus ambiguus (Photo: Neil Crouch) B P. brevicaulis (Photo: Jean Bosser) C P. brevimentus (Photo: Neil Crouch) D P. ciliatus (Photo: Neil Crouch) E P. fruticosus (Photo: Neil Crouch) F P. ecklonii (Photo: Neil Crouch).

Figure 9. Species of Plectranthus 2. A Plectranthus papilionaceus (Photo: Patrick Ranirison) B P. purpuratus subsp. montanus (Photo: Neil Crouch) C P. saccatus var. longitubus (Photo RBG Kew) D P. vestitus (Photo: Patrice Antilahimena).