Costus spectabilis K. Schum.
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 spectabilis

description: <b> 22. <i>Costus spectabilis</i> (Fenzl) K.Schum.</b> — Plate 4c; Map 13 <i>Costus spectabilis</i> (Fenzl) K.Schum. (1892) 422; (1904) 421. — <i>Cadalvena spectabilis</i> Fenzl (1865) 140. — <i>Kaempferia spectabilis</i> (Fenzl) Baker (1898) 297. — Type: <i>Boriani s.n.</i> (holo W destroyed), Sudan, Fazughli (‘in Aethiopiae terra Fassoglu’). The following collection is selected here as neotype: <i>Schweinfurth 1345</i> (neo BM,designated here; isoneo G, K, L, P), Sudan, Gallabat (‘Am linken Ufer der Gendua’), June 1865. A drawing in the B herbarium with annotation: ‘ 18 Juni 1865, Ethiopia, in Gallabas, an der Gendua’ is probably made of <i>Schweinfurth 1345</i>, the present neotype of this species. <i>Costus pistiifolius</i> K.Schum.(1892) 424. — <i>Cadalvena pistiifolia</i> (K.Schum.) Baker (1898) 297. — Type: <i>Von Mechow 315</i> (holo B destroyed; lecto Z, designated here), Angola, Prov. Malanje, Malanje (‘Malandsche’), Oct. 1879. <i>Cadalvena dalzielii</i> C.H.Wright (1912) 195; C.H.Wright (1915) t. 3013, syn. nov. — Type: <i>Dalziel 229</i> (lecto K, designated here), Nigeria, Yola Prov- ince, Kilba Country, 30 July 1909; other syntype: <i>Dalziel 560</i> (K 2 sheets, E 2 sheets), Nigeria, South of Sokota Province and throughout Kontagora Province, 12 June 1911. Terrestrial shootless rosulate herb to c. 0.1 m tall; rhizomes vertically directed, to c. 18 cm deep; horizontal runners to 5–20 cm long, (1–) 3–9 mm diam, both rhizomes and runners covered with brownish, imbricate, membranous sheaths; roots with side roots up to c. 10 cm long. <i>Leaves</i> 4 per shoot, forming a funnel when young, later spreading horizontally and forming a rosette of partly overlapping leaves flat on the ground; ligule and petiole absent; lamina bright yellowish green above, paler green with reddish venation to completely reddish below, often with (dark) reddish margins 0.5–1 mm wide, definitively thick- ened and fleshy, imbricate, broadly obovate to broadly elliptic to suborbicular, 4–15(–17) by 4–17 cm, upper side glabrous, lower side densely covered with soft, erect hairs &lt;1 mm long, margin ciliate, base attenuate, extreme base of leaf fleshy to c. 5 mm thick and 10–35 mm long, at an angle of 90° with the lamina surrounding the inflorescence, apex obtuse and often mucronate. <i>Inflorescence</i> terminal, formed in the centre of the rosette, up to 17-flowered, basally enclosed by the more or less overlapping fleshy extreme base of the leaf laminas and by the uppermost 4–5 (whitish and fleshy) sheaths; sheaths 2–4 by 1.5–3.5 cm, apex rounded, upper part reflexed with a horizontal rim of 0.7–0.8 cm high, together forming a cup of 0.8–2.5 cm diam around the inflorescence; the uppermost sheaths, outer side of bracts, bracteoles, calyx and apex of ovary densely to sparsely covered with soft, erect hairs &lt;1 mm long to glabrous, capsule glabrous. <i>Flowers</i> 1 per bract, erect; bracts reddish, membranous, narrowly triangular, 1.7–3.2 by 0.6–0.8 cm, callus yellow, inconspicuous; appendages absent; bracteole boat-shaped, 8–25 mm long, callus absent; calyx reddish, green, or purple, 15–30 mm long, split on one side, lobes 2, narrowly triangular, c. 1 mm long, callus inconspicuous; corolla hyaline, pale yellow to pale orange, 40–100 mm long, glabrous, tube 20–45 mm long, lobes narrowly ovate-triangular, 20–55 mm long; labellum dark yellow to orange, horizontally flattened, obtriangular to obovate to suborbicular when spread out, 50–70 by 30–50 mm, margin crenate; stamen orange to yellow, 15–40(–60) by 5–7 mm, anther 4–7(–12) mm long. <i>Capsule</i> subterranean, ellipsoid, 6–12 by 4–7 mm. <i>Seeds</i> c. 2 by 2 mm. ((<b>Map 14</b> Distribution of <i>Costus phyllocephalus</i> K.Schum. Distribution — North Africa (Egypt); North East Africa (Ethiopia, South Sudan, Sudan); West Africa (Benin, Burkina Faso, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Mali, Niger, Ni- geria, Senegal, Sierra Leone, Togo); Central Africa (Burundi, Cameroon, Central African Republic, Chad, Congo Brazzaville, Congo Kinshasa, Gabon); East Africa (Kenya, Tanzania, Ugan- da); Southern Tropical Africa (Angola, Malawi, Mozambique, Zambia, Zimbabwe). Habitat &amp; Ecology — Often in savanna woodland (with e.g. <i>Brachystegiae</i>, <i>Primary</i>, etc.), on clayey to loamy soil, or on rocky outcrops, often on ant hills, at elevations of 0–2000 m. Flowering and fruiting: April to December, mostly in October and December. Field observations — Completely leafless flowering specimens have been collected in May– June and October–De- cember. Information on the labels of <i>Michel &amp; Reed 70</i> and <i>Schlieben 1560</i> mentions the appearance of <i>C. spectabilis</i> soon after burning. IUCN Conservation Status — Least Concern. Notes — <i>Costus spectabilis</i> can be recognized by its four horizontally spreading leaves forming a cruciform rosette flat on the ground, with an inflorescence in the centre producing large yellow flowers. For morphological differences between <i>C. spectabilis</i> and the only other shootless rosulate species <i>C. macranthus</i> see under the latter. Both <i>C. spectabilis</i> and <i>C. macranthus</i> occur in the region between E28–35° and S6–15° in Malawi, Mozambique, Tanzania, Uganda, Zambia and Zimbabwe.All collections of <i>C. spectabilis</i> have been found in an area where <i>C. macranthus</i> has also been collected. However, <i>C. spectabilis</i> has been collected in a much wider area than <i>C. macranthus</i>: between W13° – E33° and N12° – S15° and therefore in more countries, especially in Western Africa (see map 1 of Lock 1984).
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 pages 310-311, DOI: 10.3767/000651916X694445, http://zenodo.org/record/7570023