Coleus piscatorum 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 piscatorum Meerts & A. J. Paton sp. nov.

Fig. 15 A – D

Type.

DR. Congo, Haut-Katanga, Upemba National Park, Munoï, bifurcation Lupiala , 890 m elev., 2 Jun 1948, G. F. de Witte 3897 (holotype BR [ BR 0000017708043 ]) .

Diagnosis.

Closely related to Coleus efoliatus De Wild. , differing in the shorter pedicels (1.5 vs. 2–6 mm), shorter fruiting calyx (4.5 mm long vs. 5–10 mm), with all 5 subequal triangular lobes (vs. upper lobe ovate) and the longer corolla (ca. 10 mm long vs. 3–5 (– 6) mm); also closely related to C. mystax , differing in the lack of long cilia in the inflorescence, the longer corolla and the divaricate branching pattern.

Description.

Annual herb, ca. 0.30 cm high. Stem erect, sharply quadrangular, shiny, sparsely pubescent, with very short retrorse and long patent hairs, with a tuft of hairs at nodes, branched in the upper two-thirds, with 3–5 pairs of opposite branches, almost horizontal to ascending at a broad angle, divaricate, slender, 1–8 cm long, each with 1 or 2 levels of dichotomous ramifications. Leaves almost all absent at flowering; blade ovate, ca. 2 × 1 cm, base rounded, apex narrowly subobtuse, somewhat pubescent on both surfaces, with pale sessile glands on lower surface, margin entire, secondary veins ca. 2 pairs, inconspicuous; petiole 0–1 mm long. Inflorescence seemingly terminal, actually lateral on ultimate node of twigs, slightly congested, 3–7 mm long, racemiform, rachis with short patent eglandular and glandular hairs, 1 (– 2) flower (s) in the axil of each bract, occasionally subopposite, bracts linear, ca. 1 mm long, pedicels 1–1.5 mm long, pubescent as rachis, inserted slightly eccentrically in front of upper calyx lobe. Flower: calyx ca. 2.5 mm long at anthesis, with short patent glandular and eglandular hairs and pale sessile glands, fruiting calyx ca. 4.5 mm long, whitish-membranous or chartaceous, tube tubular to campanulate, ca. 2 mm long, all lobes more or less similar in shape and size, narrowly triangular, ca. 2–2.5 mm long, acute, with thickened margin; median lobes of lower lip slightly longer; corolla blue, ca. 10 mm long, tube straight, ca. 3 mm long, progressively expanding to throat, lower lobe ca. 5 mm long, 3 mm deep, cucullate, enclosing stamens, thinly puberulent, upper lobe ca. 2 mm long. Nutlets pale brown, shiny, smooth, somewhat lenticular, ca. 1 mm.

Etymology.

Latin piscator - oris, fisherman; the species is used to impregnate fishing nets to attract fishes.

Distribution.

Endemic of SE DR. Congo (Haut-Katanga).

Habitat and ecology.

Shrub savannah, 890 m elev.

Additional specimens.

None, known only from the type specimen.

Note.

Vernacular name: lukakatjila (in kiluba).

Figures

Figure 15. Coleus piscatorum Meerts & A. J. Paton A habit B detail of inflorescence C flower D fruiting calyx (G. F. de Witte 3897). Scale bars: 1 cm (A); 2 mm (B); 1.25 mm (C); 1 mm (D). Drawn by Hilde Orye.