Aframomum ngamikkense Eb.Fisch., Kirunda, Ewango, M.E.Leal & Plumptre, 2017

Fischer, Eberhard, Kirunda, Ben, Ewango, Corneille, Leal, Miguel, Kujirakwinja, Deo, Bamba, Arcel & Plumptre, Andrew J., 2017, A new species of Aframomum (Zingiberaceae) from D. R. Congo, Phytotaxa 298 (3), pp. 277-282 : 278

Aframomum ngamikkense Eb.Fisch., Kirunda, Ewango, M.E.Leal & Plumptre , spec. nov. ( Fig. 1 , 2 )

Differt ab Afromomo pseudostipulare ligulis brevioribus obtusisque usque ad 5 mm longis (ligulae acutae et usque ad 10 mm longae in A. pseudostipulare ) et apice staminae indistincte trilobata (apex distincte trilobata in A. pseudostipulare ).

The new species differs from Aframomum pseudostipulare in the shorter and obtuse ligules up to 5 mm long (acute and up to 10 mm long in A. pseudostipulare ) and the indistinctly 3-lobed apex of the stamen (distinctly 3-lobed in A. pseudostipulare ).

Type: — D. R. CONGO. Katanga Province, Kizamba area on the trail to to top of Kankamana Hill (Long: 29.20303 E; Lat: 5.38225 S), 1570 m, 29 January–1 February 2007, B. Kirunda 32 (holotype NHN!; isotypes BR!, MHU!, LWI!) .

Rhizomes 2–3 mm in diameter, scales membranaceous. Leafy shoots 51–105 cm tall. Leaves with reticulate sheath: petiole up to 3 mm long, reflexed asymmetrically, ligules rounded and obtuse at apices, up to 5 mm long: lamina linearlanceolate with attenuate base, slightly asymmetric, apex acuminate, progressively acuminate, acumen coriaceous, glabrous, up to 15–22 × 1–1.6 cm, upper and lower surface glabrous, lateral veins more visible on lower surface. Inflorescence with up to 2 flowers, arising at base of leafy shoots, up to 5–6 cm long. Peduncle 3–4 cm long, with up to 5 or 6 scales; bracts membranaceous, basal bracts 15–20 × 8–9 mm, ovate, obtuse, upper bracts 30–35 × 9–10 mm. Calyx spathaceous, 30–35 mm long. Petals pink, tube up to 30 mm long, lateral lobes 20–30 × 5 mm, glabrous, upper lobe 15 × 30 mm, rounded at apex, labellum pink, with yellow spot at middle, 45 mm long, upper part ovate, 45 × 25–30 mm. Free filament ligulate, anthers subterminal, 10 mm long, with small hairs on back, apex indistinctly 3-lobed, terminal lobe triangular, lateral lobes less than 1 mm long. Style up to 40 mm long, stigma cupulate. Ovary 10 mm long. Fruit unknown.

Etymology: —The new species is named after the proposed Ngamikka National Park in the Misotshi-Kabogo Massif. This includes the mountains Nganja, Misotshi, Kabogo and Kabili ( Plumptre et al. 2010).

Distribution and ecology: —Primary montane forest at elevations of 1500–2000 m, growing in large gregarious patches under closed canopy, mainly on slopes, in riverine vegetation, and on hill tops. Plants flower more commonly at the peak of the rainy season from October to November, than near the end of the rainy season in February and March. The type specimen (B. Kirunda 32) was collected at 1570 m in Allanblackia kimbiliensis Spirlet , Pentadesma butyracea Sabine and Garcinia volkensii Engl. dominated forest. A second collection was made at 1905 m in Aphanocalyx cynometroides Oliv. dominated forest.

Additional material studied (paratype): —D. R. CONGO. Katanga , along the trail from Kindingi to Wimbi Port (Long: 29.09663 E; 5.24516 S), 1905 m, 4 November 2012, B. Kirunda 1278 ( NHN!) .

Notes: —The Misotshi-Kabogo Massif has been identified as an area of high endemism where three new mammal and possibly six new frog species have been discovered ( Plumptre et al. 2008; Plumptre & Menegon unpublished data). In addition, a new species of Ancistrocladus Wallich (1829: 1052) ( Ancistrocladaceae ) and a new species of Dorstenia Linnaeus (1753: 121) ( Moraceae ) are in the process of being described or already published ( Leal 2014). The rare Albertine Rift endemic Polystachya winigeri Eb.Fisch. & Killmann (2007: 93) has been collected here; the latter was previously only known from Kahuzi-Biega National Park in Eastern D.R. Congo and Nyungwe National Park in Rwanda.

Figures

FIGURE 1. Aframomum ngamikkense. A, habit; B, leaf sheaths and ligule; C, ligule; D, inflorescence; E, flower, frontal view; F, flower, lateral view; G, anther.All drawn from the type by E. Fischer.

FIGURE 2. Aframomum ngamikkense. A–B, habit; C, flower, frontal view. Photograph: A. Plumptre, of the type specimen (B. Kirunda 32).