Barleria sceptrum-katanganum Champl (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 : 87-89

Barleria sceptrum-katanganum Champl ., sp. nov.

Barleria velutinae affinis sed propter habitum robustiorem, caulem rectam largiorem, spicam longiorem, bracteas foliaceas magnas calyces occultantes et corollam lobis superis semper praesentibus vel majoribus, foliaque majora bene differt.

– Type: D.R.Congo, District du Haut-Katanga, Dubié, Jun. 1956, Duvigneaud 3676 Ac3, fl (holo-: BRLU; iso-: BR, K).

Suffrutex 25–60 cm high with a thick woody rootstock; stems erect, robust, 3–6 mm in diameter, densely and antrorsely yellowish-hairy. Leaves subsessile; lamina narrowly elliptic to lanceolate, acute at the tip, cuneate to subrounded at the base, densely and softly adpressed-hairy below, scabridulous above, 5.5–12.5 × 1.8–3 cm, 3.5 × 0.8 cm on young resprouting shoots; (4–)6–9 lateral nerves, all nerves prominent below, inconspicuous above. Inflorescence a terminal dense subcylindrical spike 4–15 × 3.5–5 cm (up to 7 cm wide at the base in fruits), with imbricate foliar bracts hiding the calyces; bracts narrowly elliptic, similar to the leaves but smaller, 2.5–4 × 0.6–1.5 cm; bracteoles smaller and narrower, tri-parallelinerved; calyx with posterior and anterior lobes similar but the anterior one slightly shorter and sometimes emarginate, both elliptic to widely ovate, irregularly and coarsely toothed in the upper 2/3 to 3/4 of their length, 2–2.5 × 1.4–2 cm, densely and softly adpressed hairy on both faces; corolla white, fading pale blue, 4–4.5 cm long, tube 2.5–3.3 cm long, subcylindrical, a bit narrowed at 10–14 mm high; limb with two upper lobes almost twice smaller than the three lower ones; upper lobes elliptic-oblong, 10–11 × 4–5 mm, rounded at the tip; lower lobes obovate, rounded and mucronate at the tip, the median one 17 × 14 mm, the lateral ones 17 × 11 mm; filament of stamens shortly and sparsely hairy at the base, filament of the two fertile stamens 12.5 mm long, anthers 2.8 mm long; three staminodes, the median with a filament 2 mm long, the two lateral ones with a filament 3.5 mm long, all bearing reduced anther with one theca 1 mm long and the other very tiny, but both types of thecae containing apparently well developed pollen grains; style about 3 cm long, glabrous, stigma short, infundibuliform. Capsule glabrous, rather shiny, brown to black, 17–20 × 5–6 mm, normally 4-seeded, but containing only two mature seeds, with in addition one very reduced, not matured seed and one completely aborted. Seeds oblong, 8 × 5 m, with hygroscopic hairs at the margin. Fig. 5 .

Distribution – Species of the Zambezian centre of endemism. Fig. 6 .

Other collections examined – D.R.Congo. District du Haut-Katanga: Rivière Lofoi, 1891, Descamps s.n., fl (BR); colline Lusanga, Jun. 1954, Desenfans 6375 (BRLU); 25 km W de Kasenga, s.d., Duvigneaud 1395, fr (BRLU); Mitwaba–Kimbo, 1956, Duvigneaud 2742, fr (BRLU, BR); Fungurume, alt. 1165 m, Apr. 1940, Quarré 6375, fl (BR).

Zambia: Kitwe, Mar. 1964, Mutimushi 674, fl, young fr (K).

Habitat – Brachystegia bussei or Brachystegia utilis­ Monotes woodland, Pseudoberlinia woodland around 1150 m (D.R.Congo); museshi woodland (Zambia).

Figures

Figure 5 – Barleria sceptrum­katanganum. A, habit in fruit; B, bract; C, from above to beneath, posticous and anticous calyx lobes (A–C, Duvigneaud & Timperman 2742).

Figure 6 – Distribution map of Barleria sceptrum­katanganum.