Chamaecostus manausensis Maas & H.Maas, 2023

Maas, Paul J. M., Maas-van de Kamer, Hiltje, Andre, Thiago, Skinner, David, Valderrama, Eugenio & Specht, Chelsea D., 2023, Eighteen new species of Neotropical Costaceae (Zingiberales), PhytoKeys 222, pp. 75-127 : 75

Chamaecostus manausensis Maas & H.Maas sp. nov.

Diagnosis.

Chamaecostus manausensis sp. nov. (Fig. 1 ) looks quite similar to C. congestiflorus and has been regularly confused with that species but can be distinguished by a narrowly cylindric (instead of broadly obovoid) inflorescence and a non-fimbriate labellum.

Type.

Brazil. Amazonas: Maua Road , 22 Mar 1971, Prance, Coêlho, Kubitzki & Maas 11529 (holotype: U 2 sheets: U1219716 & U1219717; isotypes: BR, COL128233, CR, DAV, E, F175333, F1842269, GH, INPA, K, MO, NY, P, S, US, VEN, W).

Description.

Herb 0.4-1 m tall. Leaves sheaths 2-15 mm diam; ligule 1-2 mm long; petiole 0-5 mm long; sheaths, ligule and petiole densely puberulous; lamina 13-25 × 3-6 cm, narrowly elliptic, adaxially sparsely puberulous to glabrous, abaxially sometimes reddish-purple, sparsely to densely puberulous, particularly the primary vein, base obtuse, apex acuminate, acumen 5-15 mm long. Inflorescence 4-10 × 1.5-3 cm, up to ca. 13 × 4 cm in fruit, narrowly cylindric, terminating a leafy shoot; bracts, bracteoles, calyx, ovary, and capsule rather densely to densely puberulous; bracts 2.5-3.5 × 0.3-0.5 cm, narrowly triangular, green, chartaceous, apex often mucronate, callus 3-6 mm long; bracteole 15-20 mm long, tubular, often deeply split on the abaxial side, 2-lobed, lobes 3-7 mm long, deltate. Flowers calyx 20-33 mm long, green, tube often deeply split during anthesis, lobes 5-10 mm long, subulate; corolla 50-65 mm long, cream, densely puberulous, lobes 30-40 mm long narrowly, obovate; labellum ca. 35 × 40 mm, cream, distal edge horizontally spreading, broadly angular-obovate, margin crenulate; stamen 25-30 × 10 mm, cream, apex reflexed, irregularly dentate, anther 5-6 mm long. Capsules 11-13 mm long, ellipsoid.

Distribution.

Brazil (Amazonas, Pará) (Fig. 21A ).

Habitat and ecology.

In terra-firme rainforests or campinarana vegetation, on sandy or clayey soils, at elevations of about sea level. Flowering and fruiting: October to March, July.

Etymology.

This species is named “manausensis” after the city of Manaus, State of Amazonas, Brazil, where this species is most commonly distributed.

Paratypes.

Brazil. Amazonas: Reserva Florestal Ducke, km 26 of Manaus-Itacoatiara road, 1 Dec 1994, Assunção 107 (INPA, U), 5 Jan 1995, Costa et al. 73 (INPA, U), 12 Dec 1996, 568 (INPA, U), 10 Oct. 1995, Miralha & Maas 296 (INPA, U), 26 Jan 1995, Nascimento & Silva 726 (INPA, U); Cachoeira Alta do Tarumã, Manaus, 7 Feb 1930, Ducke RB 25622 (U); Rio Maués-Acú, across from Maués, Mun. Maués, 21 Jul 1983, Hill et al. 13138 (INPA, MG, NY, RB, US). Pará Floresta Nacional do Tapajós, comunidade Jamaraquá, Mortati 92 (HSTM).

Notes.

For additional field data, see Costa et al. (2011), where this species has been treated under the name Costus congestiflorus .

Figures

Figure 1. Chamaecostus manausensis Maas & H. Maas A plant in habitat Floresta Nacional do Tapajos, Brazil B flower showing the non-fimbriate margin of the labellum C, E inflorescence narrowly cylindric instead of broadly obovoid D sheath and ligules. Photos A-E by Thiago Andre.

Figure 21. Distribution maps for new species of Costaceae: Chamaecostus - Costus douglasdalyi A Chamaecostus manausensis Maas & H. Maas B Costus alfredoi Maas & H. Maas C Costus alleniopsis Maas & D. Skinner D Costus alticolus Maas & H. Maas E Costus antioquiensis Maas & H. Maas F Costus callosus Maas & H. Maas G Costus cochabambae Maas & H. Maas H Costus convexus Maas & D. Skinner I Costus douglasdalyi Maas & H. Maas.