Barleria pauciflora 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 : 92-94

Barleria pauciflora Champl. , sp. nov.

B. neurophylla C.B.Cl. valde affinis sed propter calycis lobos integros, nec minute dentatos vel erosos nec extra marginem longe patenter ciliatos, nec subscariosos; propter folia longitudinis in latitudine rationem 3,6 nec 2,5 et corollae lobos satis multo angustiores bene differt

– Type: D.R.Congo, District du Haut-Katanga, chutes Dikolongo, près de Lubudi, alt. 1230 m, Apr. 1985, Malaisse & Goetghebeur 283, fl (holo-: BR; iso-: B, CAS, K, MO, P, WAG).

Suffrutescent plant up to 70 cm high. Stem with two opposite bands of rather sparse antrorse hairs or antrorsely pubescent all around. Lamina of the leaves elliptic to narrowly elliptic or oblanceolate, acute to acuminate at the tip, cuneate to attenuate at the base, 3.3–12.5 × 0.9–3.9 cm, sparsely covered with short adpressed hairs; 4–8 lateral nerves; petiole 3–8 mm long. Inflorescence terminal, capitate, few-flowered, sometimes with solitary axillary flowers at one or two nodes below the terminal part or with small lateral inflorescences on short shoots; bracteoles linear, up to 1 cm long; calyx with posticous lobe suborbicular-subrhomboidal, entire, acute at the tip, 13–20 × 10–19 mm; anticous lobe similar, 12–18 × 8–17 mm, shortly bifid at the tip, both adpressed-pubescent mainly on the nerves outside, puberulent inside; lateral lobes narrowly lanceolate, 7–10 mm long; all lobes accrescent in fruit; corolla blue or blue-mauve, 2.7–3.2 cm long, with four lobes bending upwards and one lower lobe; tube 18 mm long, 7-10 mm wide at the throat; the two median upper lobes narrowly oblong, 7–10 × 3–5.5 mm; the two upper lateral obovate-oblong, 8–13 × 4–8 mm and the lower one similar but broader, 9–11 × 9–10 mm; fertile stamens 2, filament glabrous 15 mm long, anther 3 mm long, 2 staminodes with filament 2 mm long; style glabrous, 18 mm long, stigma capitate; filaments and style exserted out the mouth of corolla but shorter than the lobes. Capsule 12 × 4–5 mm, ellipsoid, blackish. Seeds two, brown. Figs 3C & 10 .

Key to the vicariant pair B. neurophylla / B. pauciflora

1. Calyx lobes minutely toothed or erose, margin transcended at length by thin spreading bristles; leaves maximum 2.5 times longer than wide, with long adpressed hairs up to 2 mm long; corolla lobes 9–14 mm wide........................................................................................................................... B. neurophylla

1. Calyx lobes entire, margin not transcended by long thin spreading bristles but provided with short adpressed-antrorse hairs; leaves 3.6 times longer than wide, with short adpressed hairs less than 1 mm long; corolla lobes 3–10 mm wide....................................................................................... B. pauciflora

Distribution – Species of the Zambezian centre of endemism. Endemic to Katanga. Fig. 11 .

Other collections examined – D.R.Congo. District du Haut-Katanga: Rivière Kamandula, Jun. 1949, de Witte 6480, fl (BR, C); ibid., Jun. 1949, de Witte 6915, fl (BR); rivière Panda, Apr. 1943, Hoffmann 490, fl (BRLU); rivière Mwera, Apr. 1980, Malaisse 10514, fl (BR, K, UPS); Sampwe, rivière Kaluke, Jul. 1939, Quarré 5805, fl (BR); ibid., Jul. 1939, Quarré 5835, fl (BR); riv. Mwera, 56 km NNW Lubumbashi, alt. 1200 m, May 1983, Schaijes 1922, fl (BR).

Habitat – Gallery forests, around 1200 m a.s.l.

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 10 – Barleria pauciflora. A, habit; B, from above to beneath, posticous and anticous calyx lobes; C, opened corolla (A, de Witte 6915; B & C, de Witte 6480).

Figure 11 – Distribution map of Barleria pauciflora and B. neurophylla.