Coleus kundelunguensis Meerts & A. J. Paton, 2024

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 kundelunguensis Meerts & A. J. Paton sp. nov.

Fig. 7 A – D

Type.

S. Lisowski, F. Malaisse & J.-J. Symoens 7626, DR. Congo, Katanga, Kundelungu , 1650 m elev., steppe humide, 28 Oct 1969 (holotype POZG [ POZG-V-0073133 ]) .

Diagnosis.

Related to C. foliatus , differing in the very lax inflorescence with verticils spaced 10–25 mm, the longer pedicel jointed near the middle, the anthers not forming a pouch and the bifid style.

Description.

Perennial herb 0.30–0.50 m high, shoots more or less tufted, more or less woody at base, rootstock rhizomatous. Stem subterete, erect to ascending, simple or sparingly branching, shortly pubescent with patent eglandular hairs of different lengths, almost papilliform in the inflorescence, sparse glandular hairs and yellow sessile glands. Leaves opposite, ascending to erect, sessile to subsessile, ca. 4–6 pairs to a stem, widely spaced, petiole 0–0.2 cm long, blade ovate to ovate-elliptic, or obovate-elliptic, (1.2 –) 2.0–5.5 (– 7.5) × (0.5 –) 0.6–2.0 cm, base broadly cuneate to rounded, occasionally truncate to subauriculate in the uppermost leaves, apex acute to obtuse, more rarely acuminate, margin crenate to subentire, narrowly recurved, very shortly pubescent near margin and on lower surface of mid-vein, punctuate on both surfaces, drying dark reddish-green especially on veins. Inflorescence mostly unbranched, occasionally with a pair of branches at base, 4–20 cm long, very lax, rachis somewhat flexuose, verticils spaced 10–25 mm, flower solitary in the axil of each bract, with 1 or 2 flowers at each node, bract narrowly ovate to linear, 2–5 mm long, acute, pedicel 5–7 mm long at anthesis, elongating to 8–17 mm in fruit, very shortly pubescent (hairs almost papilliform, eglandular), conspicuously jointed and slightly angled slightly above middle, inserted asymmetrically in front of upper calyx lobe. Flower: calyx 4 mm long at anthesis, 9–10 mm long in fruit, tube straight to very slightly curved, 6–7 mm long, shortly pubescent, with eglandular and glandular hairs and sparse sessile orange glands, veins prominent, throat truncate, upper lip triangular, 1.5–2.5 mm long, slightly curving upwards, not decurrent, lower lobes narrowly triangular, the middle ones longer, 2.5–3.5 mm long, all lobes shortly ciliate. Corolla ca. 12 mm long, tube 6–7 mm long, sigmoid, lower lip carenate, 5–7 mm long, slightly pubescent on carena, upper lip 4 mm long, pubescent; anthers not forming a pouch, style bifid. Nutlets pale brown, smooth, dull, ovoid to globose, ca. 1.5 mm long.

Distribution.

Endemic to the DR. Congo, Haut-Katanga, Kundelungu Plateau.

Habitat and ecology.

Steppic savannah, often on moist soil, 1600–1700 m elev.

Additional specimens.

DR. Congo, Haut-Katanga, Kundelungu, près de la source occidentale de la Lutshipuka, 1600 m elev., steppe arbustive, 6 Jan 1969, S. Lisowski 773 ( POZG); Kundelungu, bord de la Kalembe, 1600 m elev., 8 Jan 1971, S. Lisowski 23701 ( POZG); Kundelungu, 1600 m elev., près du gîte Rack, 6 Feb 1969, S. Lisowski, F. Malaisse & J. - J. Symoens 1286 ( POZG); Kundelungu, rivière Lualala, 1700 m elev., à 3 km au SE du poste de Lualala, 16 Feb 1969, S. Lisowski, F. Malaisse & J. - J. Symoens 2149 ( BR, POZG) & 2149 d ( POZG); Kundelungu, 1700 m elev., à 3 km à l’W du poste de Lualala, steppe herbacée, 27 Oct 1969, S. Lisowski, F. Malaisse & J. - J. Symoens 7468 ( POZG); Kundelungu, à 3 km de la barrière, 1590 m elev., bord de la rivière Kalunda, 9 Jan 1971, S. Lisowski, F. Malaisse & J. - J. Symoens 12592 A ( POZG).

Notes.

1. Most of the cited specimens had been hitherto misidentified in collections as the Angolan C. strictipes , from which C. kundelunguensis differs in the smaller habit, flexuous shoot, very lax inflorescence with verticils spaced 10–25 mm, the anthers not forming a pouch and the bifid style.

2. The anthers not forming a pouch and the bifid style are rare in the group of species formerly referred to Holostylon , being observed only in C. kundelunguensis Meerts & A. J. Paton and C. bifidus (A. J. Paton) A. J. Paton.

Figures

Figure 7. Coleus kundelunguensis Meerts & A. J. Paton A habit B inflorescence verticil with one fruiting calyx C flower D stamen (A S. Lisowski, F. Malaisse & J. - J. Symoens 773 & 6722 B S. Lisowski, F. Malaisse, J. - J. Symoens 6722 C, D S. Lisowski, F. Malaisse, J. - J. Symoens 7468). Drawn by Hilde Orye. Scale bars: 1 cm (A); 5 mm (B, C); 1 mm (D).