Costus albiflos Maas &amp; H. Maas 2016, sp. nov.
Creators: name: Kamer 1, H. Maas-van de
name: Maas 1, P. J. M.
name: Wieringa 1, J. J.
name: Specht, C. D.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Zingiberales
Costaceae
Costus
Costus albiflos

description: <b> 3. <i>Costus albiflos</i> Maas &amp; H.Maas</b> , <i>sp. nov.</i> — Plate 1c; Map 2 <i>Costus albiflos</i> is very easily recognizable by its leafless flowering shoot, green appendaged bracts and completely white flowers (with only a slightly yellow nectar guide). Its petiole, ligule and sheaths are covered with ap-pressed, 0.5–1 mm long hairs with a thickened base creating a ‘rough’ feeling. — Type: <i>Maas et al. 10411</i> (holo WAG 2 sheets [WAG0380170, WAG0380171]; iso BR, K, L [L.2079937], LBV, MO, P, UC), Gabon, Estuaire, side road at km 46 of road from Kougouleu to Méla, on the border of Parc National Monts de Cristal, 15 m, 21 Nov. 2011. Terrestrial herb 1–3 m tall. <i>Leaves</i> many; sheaths 1–1.5 cm diam; ligule chartaceous, 2-lobed, 10–30 mm long; petiole 5–10 mm long; sheaths, ligule and petiole rather densely covered with appressed hairs &lt;1 mm long; lamina pale green below, narrowly elliptic to narrowly obovate, 20–40 by 5–8 cm, slightly 6 –10-plicate, upper side glabrous or sparsely covered with appressed hairs &lt;1 mm long, lower side sparsely covered with appressed hairs &lt;1 mm long to glabrous, midrib rather densely so and hairs longer, base acute, apex acuminate (acu-men 15–20 mm long). <i>Inflorescence</i> many-flowered, ovoid, 4–12 by 3–8 cm, terminating a separate leafless shoot 10–50 cm long; bracts, appendages of bracts, bracteoles and calyx sparsely covered with appressed hairs &lt;1 mm long, ovary and capsule glabrous. <i>Flowers</i> 1 per bract; bracts green, coriaceous, broadly ovate, 1.5–2 by 1–2.5 cm, callus absent; append-ages green, horizontally spreading, broadly ovate-triangular to ovate-triangular, 1–3.5 by 1–2.5 cm; bracteole boat-shaped, 18–20(–25) mm long, with 1 or 2 calli 1–1.5 mm long; calyx 9–14 mm long, lobes ovate-triangular, 2–4 mm long, callus absent; corolla white, 50–55 mm long, glabrous, tube c. 15 mm long, lobes narrowly ovate, 35–40 mm long; labellum white, inner side sometimes with a pale yellow nectar guide, horizon-tally flattened, broadly obovate when spread out, 30–35 by 30 mm; stamen white, 30–40 by 10 mm, anther 5–6(–9) mm long. <i>Capsule</i> ellipsoid, 10–15 by 6–8 mm. <i>Seeds</i> 1–2 by 1–2 mm. Distribution — Central Africa (Cameroon, Gabon). Habitat &amp; Ecology — In lowland rainforest, often near streams, at elevations of 0– 700 m. Flowering and fruiting: February, April and May. IUCN Conservation Status — Based on an AOO of 40 km 2 from seven locations of which only one is part of a National Park, while most others face several logging threats, we assess this species as Vulnerable (VU): B2ab(ii,iii,iv). <i>Other specimens examined</i>. CAMEROON, <b>South Province</b>, Collines BOG, 5 km W of Atogboga (25 km NNE of Bipindi), 30 Jan. 1974, <i>Letouzey 12829</i> (P); Colline Nkol Tsia, 18 km NW of Bipindi, near Gouap, 488 m, 5 Feb. 1974, <i>Letouzey 12913</i> (P); Nyangong, transect 8, 700 m, 12 Dec. 1996, <i>Van Gemerden 101</i> (WAG). <b>South-West Province</b>, Ndian, Ekundu Kundu, 200 m, 26Apr.1996, <i>Cheek et al. 8204</i> (K, WAG). – GABON, <b>Estuaire</b>, Crystal Mountains, 3 km along track Alen Nkomo-Andok Foula, 30 m, 21 Nov. 1986, <i>J.J.F.E</i>. <i>de Wilde et al. 8895</i> (LBV, MO, WAG); Parc National de Monts de Cris-tal, road L108 from Kinguélé to Tchimbélé, past Kinguélé, c. 300 m, 24 Oct. 2011, <i>Maas et al.9968</i> (LBV, WAG). <b>Woleu-Ntem</b>, Chantier Oveng,c. 500 m, 7 May 1986, <i>A.M. Louis 2185</i> (LBV, WAG); Crystal Mountains, 1 km S of Tchimbélé, 450 m, 14 Nov. 2004, <i>Wieringa et al. 5423</i> (WAG).
description: Published as part of <i>Kamer 1, H. Maas-van de, Maas 1, P. J. M., Wieringa 1, J. J. &amp; Specht, C. D., 2016, Monograph of African Costaceae, pp. 280-318 in Blumea 61 (3)</i> on page 293, DOI: 10.3767/000651916X694445, http://zenodo.org/record/7570023