Barleria cinnabarina Champl., 2011

Dominique Champluvier, 2011, New and overlooked Acanthaceae taxa from D. R. Congo, Rwanda and Burundi: (1) the genus Barleria, Plant Ecology and Evolution 144 (1), pp. 82-95 : 91

Barleria cinnabarina Champl. , sp. nov.

Ab omnibus Barleriae speciebus propter corollam cinnabarinam cum lobos superos minutissimos, folia minutissima in spine desinentia, ramos crassos et habitum fruticosum bene distinguitur.

– Type: D.R.Congo, District du Haut-Katanga, Mitwaba–Manono, Jun. 1988, Pauwels 7153, fl (holo-: BR; iso-: CAS, K, MO).

Prostrate subshrub or bushy erect shrub 1–2 m high; branches tomentose, dark brown, thick. Leaves subsessiles, lamina of the leaves very small, elliptic, thick, 8–17 × 3–10.5 mm, densely pubescent on both faces, cuneate at the base, tip abruptly ending in a sharp spine 1.5–3 mm long; nerves depressed above (fresh material), prominent below. Flowers solitary, terminal and axillary on short lateral branches; bracteoles spiny, linear, 2 cm long, divergent; calyx lobes papery; posticous calyx lobe elliptic, 14–19 × 4.5–8 mm, acute-spiny at the tip; anticous one similar, 12–16 × 4.5–8 mm; lateral lobes 9 × 2 mm; corolla vermilion red, 36–38 mm long, tube 21–22 mm long, 6–8.5 mm wide under the lobes; upper lobes rudimentary, 2–3 × 1.75–2 mm, recurved laterally; lower lobes widely elliptic, the median one 14–15 × 9.5–10 mm, the lateral ones 15–16 × 10–11 mm; fertile stamens 2, filament 37–39 mm long, exserted, glabrous; anther 4.5 mm long and, in addition, two or three staminodes with or without shorter anthers; style 29 mm long, exserted, glabrous, stigma cylindrical. Capsule ellipsoid, blackish, 14–18 × 5 mm. Seeds two, dark brown when dry. Figs 3B & 9 .

Distribution – Species of the Zambezian centre of endemism. Endemic to Katanga. Fig. 8 .

Other collections examined – D.R.Congo. District du Haut-Katanga: Kibara, Jul. 1952, Delvaux 420, fl (BR); région de Mitwaba, Desenfans s.n., sterile (BRLU); Kitshinje, alt. 1400 m, May 1953, Desenfans 3074, sterile (BRLU); route Selkibara S, Aug. 1953, Desenfans 3877, fl (BRLU); Makomo, Aug. 1953, Desenfans 3887 (BR, BRLU); P.N. Upemba, Aug. 1953, Desenfans 3887, fl, fr (BR); 15 km S de Mitwaba, Jan. 1960, Duvigneaud 5080 Ac, sterile (BRLU); Mitwaba, 1956, Duvigneaud & Timperman 2702 Ba, fr (BRLU); Km 20 Mitwaba–Manono, Jul. 1952, Galoux 180, fl, fr (BR); 10 km nord de Mitwaba, Sep. 1959, Schmitz 6617, fl, fr (BR); s.l., s.d., Vandenbrande M 204, sterile (BRLU).

Habitat – Savannas on rocky soils, seepings on granites, dry bushy savannas and woodlands on quartzites, rocks, alt. 1400–1600m.

The red corolla with extremely reduced upper lobes and the scarious calyx lobes – both latter characters also present in B. bremekampii from sect. Barleria ( Balkwill & Balkwill 1997) – allow to place B. cinnabarina in the same section. The only difference, two seeds instead of four, is perhaps due to possible abortion of two of the ovules and to the scarcity of fruiting material and of the number of specimens, not allowing a representative set of fruits.

B. bremekampii differs in its leaves reaching 1.5 × 0.9 cm, without terminal spine and not coriaceous, its spiny bracteoles 1.6 cm long, its outer calyx lobe 12 × 4 mm, its 2.4 cm long corolla with a tube 2 cm long, upper lobes 3 × 3 mm, not recurved laterally, lateral ones 10 × 7 mm and the lower one 10 × 9 mm, its 15 mm long stamens and 4 mm long anthers, and its 2 cm long style.

Figures

Figure 3 – Plants in flower. A, Barleria velutina (photo: Michel Schaijes); B, Barleria cinnabarina (photo: Luc Pauwels); C, Barleria pauciflora (photo: Michel Schaijes); D, Barleria kaessneri (photo: Michel Schaijes).

Figure 8 – Distribution map of Barleria lobelioides and Barleria cinnabarina.

Figure 9 – Barleria cinnabarina. A, habit; B, leaf; C, from left to right, anticous and posticous calyx lobes; D, opened corolla showing stamens and staminodes; E, capsule (A, Pauwels 7158; B, Galoux 180; C, D & E, Delvaux 420).