Coleus foliatus (A. J. Paton) A. J. Paton

Meerts, Pierre J. & Paton, Alan J., 2024, The genus Coleus (Lamiaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi), with the description of 15 new species, PhytoKeys 246, pp. 71-178 : 71-178

Coleus foliatus (A. J. Paton) A. J. Paton , Phytokeys 129: 46. 2019 .

≡ Plectranthus foliatus A. J. Paton , Fl. Trop. E. Afr., Lamiac.: 284. 2009. Type: Tanzania, Sumbawanga District, Tatanda, Mbaa Hill, 25 Apr 1997, S. Bidgood et al. 3459 (holotype K [ K 000194843 ], [ K 000194844 ]; isotype C, DSM, K, NHT).

Description.

Paton et al. (2009: 284), Paton et al. (2013: 234), as Plectranthus foliatus A. J. Paton.

Distribution.

SW Tanzania, N Zambia, Burundi, SE DR. Congo.

Habitat and ecology.

Steppic savannah, scrub, mostly on highlands, often on shallow rocky soil, occasionally on copper-rich soil; 1500–2000 m elev.

Additional specimens.

DR. Congo, Haut-Katanga, Marungu, Kasiki, 20 Jun 1931, G. F. de Witte 470 ( BR); Tenke, P. Duvigneaud & J. Timperman 2624 E ( BRLU); Mitwaba-hôtel, steppe, 9 Sep 1956, P. Duvigneaud & J. Timperman 2691 Co ( BRLU); Marungu, 1 km S Mont Lusale, 27 Jun 1957, P. Duvigneaud 3738 C ( BRLU); Kundelungu, 6.4 km NNW Katshupa, 17 Oct 1966, F. Malaisse 4660 ( BR, LSHI); Poste de Mitwaba, Aug 1945, G. Mortelmans 96 ( BR); Domaine de Muhila, près de Kansimba, 1400 m elev., steppe, 7 Nov 1970, S. Lisowski 23488 ( POZG).

Burundi, Route Matana-Rutovu, km 15, 26 Feb 1966, J. Lewalle 469 ( BR); Bururi, 3 Feb 1968, J. Lewalle 2760 ( BR, P); Luvironza, Bututsi, 3 Mar 1955, G. Michel 4702 ( BR).

Notes.

1. New species record for DR. Congo. Widespread on the Mitwaba and the Marungu Plateau (Haut-Katanga).

2. Coleus foliatus is more variable in leaf shape in DR. Congo and Burundi compared to neighbouring regions; specimens with unusually narrow leaves (ca. 45 × 5 mm) are found in Burundi (e. g. J. Lewalle 469, M. Reekmans 8659); they differ from C. duvigneaudii in having opposite leaves, relatively short leaf blade and blunt leaf apex. In Upper Katanga, where C. foliatus and C. duvigneaudii are sympatric, more or less intermediate specimens occur (e. g. S. Lisowski, F. Malaisse & J. - J. Symoens 1247, S. Lisowski, F. Malaisse & J. - J. Symoens 11295; A. Schmitz 3150).