Costus alfredoi 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 alfredoi Maas & H.Maas sp. nov.

Diagnosis.

Costus alfredoi sp. nov. (Fig. 2 ) is recognizable by an extremely small ligule (<1 mm long), a “basal” inflorescence (inflorescence terminates a short, leafless shoot and thus is positioned at the base of the plant) with red, unappendaged bracts and yellow, tubular flowers, an almost complete lack of indument, and very narrow, grass-like leaves. It shares the last two features with C. vargasii but differs by a shorter ligule (<1 mm vs. 5-35 mm long) and a much longer calyx (15-16 vs. 6-10 mm) and bracteole (25-27 vs. 12-22 mm).

Type.

Bolivia, La Paz: Prov. Bautista Saavedra, Area Natural de Manejo Integrado Apolobamba , between Paujeyuyo and Calzada, 1140 m, 16 Nov 2003, Fuentes Claros, Cayola, Whitehead & Cuevas 6216 (holotype: MO2098346; isotypes: U1212213 & U1212214) .

Description.

Herb ca. 2 m tall. Leaves sheaths 4-5 mm diam; ligule obliquely truncate, <1 mm long; petiole 5-7 mm long; sheaths, ligule and petiole glabrous; lamina linear, 15-23 × 1.5-2.5 cm, adaxially and abaxially glabrous, except for some hairs along the margin, base acute to obtuse, apex long-acute. Inflorescence ovoid, 11-12 × 5-6 cm, terminating a leafless shoot 50-85 cm long, sheaths obliquely truncate, 6-8 cm long, glabrous; bracts, bracteole, calyx, ovary, and capsule glabrous; bracts red, coriaceous, ovate, 3-4 × 1.5-2.5 cm, apex obtuse, callus 5-7 mm long; bracteole boat-shaped, 25-27 mm long. Flowers abaxially oriented; calyx 15-16 mm long, lobes shallowly ovate-triangular, 2-3 mm long; corolla yellow to orange, ca. 50 mm long, glabrous, lobes narrowly elliptic, ca. 30 mm long; labellum yellow, lateral lobes rolled inwards and forming a curved tube ca. 10 mm diam, oblong-elliptic when spread out, ca. 35 × 15 mm, middle lobe with yellow honey mark, 5-7-lobulate, lobules red, 5-6 mm long; stamen yellow, ca. 35 × 7 mm, slightly exceeding the labellum, apex red, slightly dentate, anther length not measured. Capsule ellipsoid, ca. 15 mm long.

Distribution.

Bolivia (La Paz) (Fig. 21B ).

Habitat and ecology.

In wet, sub-Andine forests with Oenocarpus bataua Mart.( Arecaceae ) at an elevation of ca. 1140 m. Flowering in November.

Etymology.

Costus alfredoi is named after the very active and inspiring Bolivian plant collector Alfredo Fuentes, who we personally met some years ago during a visit to the MO Herbarium and who provided us with additional data on Bolivian species of Costaceae .

Notes.

In Bolivia and Brazil, D. Skinner has observed plants with leaves and ligules that match this description. However, they were not in flower. The distribution of this species may be found to extend beyond the department of La Paz, Bolivia.

Figures

Figure 2. Costus alfredoi Maas & H. Maas A inflorescence terminal on a leafless shoot B flower C holotype from Bolivia, La Paz D detail from holotype showing narrow, grass-like leaves and short ligule. (A-D from Fuentes et. al. 6216). Photos by Alfredo Fuentes Claros.

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.