Costus pseudospiralis 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

Costus pseudospiralis Maas & H.Maas sp. nov.

Diagnosis.

Costus pseudospiralis sp. nov. (Fig. 18 ) looks superficially quite similar to C. spiralis (Jacq.) Roscoe, but differs by the orientation of the flowers (floral opening facing abaxially v adaxially) and a cordate leaf base. It differs from C. douglasdalyi by the inflorescence terminating a leafy shoot instead of terminating a shorter leafless shoot (sometimes referred to as ‘basal’ in the literature), the presence of villose indumentum on most of its vegetative parts (vs. glabrous or sparsely puberulous), and a cordate (vs. acute to rounded) leaf base.

Type.

Bolivia, Beni: km 4 of road from Riberalta to Santa María, 150 m, 22 Jan 1999, Maas, Maas-van de Kamer & Apaza 8751 (holotype U, 2 sheets: U1610003 & U1610004; isotypes K, MO, USZ) .

Description.

Herb 1.5-2 m tall. Leaves sheaths 10-15 mm diam; ligule obliquely truncate, 5-8 mm long; petiole 3-5 mm long; sheaths, ligule and petiole densely villose; lamina narrowly elliptic, 20-43 × 4-12 cm, adaxially densely to rather densely villose, abaxially densely villose, base cordate, apex acuminate (acumen 10-15 mm long). Inflorescence ovoid, 4-12 × 3-6 cm, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and capsule glabrous. Flowers abaxially oriented; bracts red to dark red, coriaceous, broadly ovate, 2.5-3.5 × 2.5-3.5 cm, apex obtuse, callus 5-7 mm long, sometimes with a small, deltate appendage c. 5 × 5 mm; bracteole boat-shaped, 15-20 mm long; calyx red, 8-11 mm long, lobes shallowly ovate-triangular to very shallowly ovate-triangular deltate, 1-2 mm long; corolla dark salmon pink, 45-50 mm long, glabrous, lobes narrowly obovate-elliptic, 30-35 mm long; labellum pale salmon pink, apex and centre white, distal part of middle lobe yellowish, lateral lobes rolled inwards and forming a slightly curved tube 6-12 mm diam, oblong-obovate when spread out, 30-35 × 20-25 mm, apex irregularly 5-lobulate; stamen salmon pink, ca. 30 × 7 mm, not exceeding the labellum, apex white, rounded, anther 8-10 mm long. Capsule ellipsoid, 10-20 mm long.

Distribution.

Bolivia (Beni), Brazil ( Rondônia) (Fig. 22G ).

Habitat and ecology.

In secondary roadside vegetation, at elevations of 150-700 m. Flowering year-round.

Etymology.

This species is named “pseudospiralis”, referring to its resemblance to C. spiralis .

Paratypes.

Bolivia. Beni: 3 km E of Riberalta on road to Guayaramerín, then 2 km SE of side road, 230 m, 7 Jun 1982, Solomon 7978 (L, LPB, MO). Santa Cruz: Prov. Velasco, Parque Nacional Noel Kempff Mercado, Los Fierros, 200 m, 8 Nov 1993, Jardim & Quevedo 56 (MO, NY, USZ); Prov. Velasco, Parque Nacional Noel Kempff Mercado, Huanchaca II, 700 m, 4 Jul 1996, Peña-Chocarro et al. 65 (U, USZ). Brazil. Rondônia: trail from Fortaleza to Rio Abuña, 20 km above mouth to São Sebastião mines, 15 Nov 1968, Prance et al. 8459 (NY, U).

Figures

Figure 18. Costus pseudospiralis Maas & H. Maas A plant in habitat near Xapuri, Acre, Brazil with Martin Acosta B inflorescences emerging from the same rhizome C close-up of inflorescence with flowers showing their abaxial orientation D inflorescence with scale, emerging flower showing abaxial orientation E abaxial leaf surface showing indument. Photos A-E by Dave Skinner.

Figure 22. Distribution maps for new species of Costaceae. Costus gibbosus - Costus whiskeycola m A Costus gibbosus D. Skinner & Maas B Costus mollissimus Maas & H. Maas C Costus obscurus D. Skinner & Maas D Costus oreophilus Maas & D. Skinner E Costus pitalito C. D. Specht & H. Maas F Costus prancei Maas & H. Maas G Costus pseudospiralis Maas & H. Maas H Costus rubineus D. Skinner & Maas I Costus whiskeycola Maas & H. Maas.