Costus prancei 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 prancei Maas & H.Maas sp. nov.

Diagnosis.

Costus prancei sp. nov. (Fig. 17 ) looks quite similar to C. sprucei Maas (a species restricted to the Brazilian state of Pará) and has been confused with it in the past, both sharing most of the vegetative and floral characters, but this species has yellow to orange flowers whereas they are pinkish red in C. sprucei .

Type.

Brazil, Acre: vicinity of Serra da Moa , 22 Apr 1971, Prance, Maas, Kubitzki, Steward, Ramos, Pinheiro & Lima 12265 (holotype U, 2 sheets: U1607120 & U1603130 (spirit collection); isotypes INPA, NY00867011) .

Description.

Herb 1-1.5 m tall. Leaves sheaths 8-10 mm diam; ligule truncate, 2-7 mm long; petiole 2-8 mm long; sheaths, ligule, and petiole densely to sparsely villose; lamina narrowly elliptic, 11-25 × 4-7 cm, adaxially densely villose to glabrous with a dense row of hairs along the primary vein, abaxially densely puberulous to villose, base acute, rounded, or cordate, apex acuminate (acumen ca. 15 mm long). Inflorescence cylindrical, 3-15 × 1.5-4 cm, terminating a leafy shoot; bracts, bracteole, calyx, ovary, and fruit densely puberulo-villose to glabrous. Flowers abaxially oriented; bracts red, coriaceous to chartaceous, broadly to depressed ovate, 1.5-2.5 × 1.5-3 cm, callus 3-5 mm long; bracteole boat-shaped, 9-15 mm long; calyx red to pale orange-red, 6-12 mm long, lobes shallowly triangular, 1- mm long; corolla yellow to orange (2 labels indicated cream and pink to orange!), 20-30 mm long, glabrous, lobes narrowly elliptic, 20-25 mm long; labellum yellow to orange, lateral lobes involute and forming a straight tube 7-8 mm diam, oblong-obovate when spread out, 20-25 × 12-16 mm, irregularly lobulated, lobules 0.5-5 mm long; stamen yellow, 23-25 × 7-8 mm, slightly exceeding the labellum, apex rounded, anther ca. 6 mm long. Capsule ellipsoid to subglobose, 6-7 × 5-7 mm.

Distribution.

Brazil (Acre, Amazonas, Rondônia), Peru (Loreto, San Martín) (Fig. 22F ).

Habitat and ecology.

In non-inundated (terra firme) or periodically inundated ( várzea) forests at elevations of 0-260 m. Flowering year-round.

Vernacular names.

Brazil: Canafiche.

Etymology.

This species is named after our friend and dearest colleague Sir Ghillean Prance, who invited us (PM and HM) in 1971 to join various of his expeditions into the Brazilian Amazon region and who inspired me (PM) very much to continue working as a Neotropical taxonomist.

Paratypes.

Brazil. Acre: Mun. Mançio Lima, Upper Rio Moa, top of Serra Azul, 12 Oct 1968, Campbell 8951 (NY, RB); Mun. Mançio Lima, Serra do Moa, 29 Dec 1998. Ehrich 5c (L, NY); Mun. Mançio Lima, PARNA, Serra do Divisor, trilha para a Cachoeira Formosa, 225 m, 21 Aug 2008, Fiaschi 3287 (NY). Amazonas: Rio Nhamundá, Assumpção & Coêlho 72 (INPA); Tapurucuara, Rio Negro, 6 Feb 1959, Cavalcante 540 (MG); Mun. Humaitá, BR 230, Rodovia Transamazonica, 126 km from Humaitá, 12 Apr 1985, Cid et al 5437 (INPA, NY); Mun. Manaus, c. 80 km NNE of Manaus, Fazenda Esteio, 50-125 m, 23 Jun 1992, Nee 42842 (NY, U); Tapurucuara, road to the airport, 16 Oct 1971, Prance et al. 15300 (COL, DAV, F, INPA, NY, U, US, VEN, W); Rio Canumã, 1 Mar 1945, Proctor Cooper s.n. (COL, US); Manaus-Itacoatiara Road, Rio Preto, km 80, 14 Nov 1966, Prance et al. 3151 (F, MO, NY, U, US); Manaus-Itacoatiara Road, Rio Preto, km 90, 19 Jul 1961, Rodrigues & Lima 2996 (INPA, U); Tapurucuara, 22 Jan 1978, Steward et al. 476 (INPA, MO, NY, U, US); Lake Canumã, Von Martius s.n. (M). Rondônia: Estrada Porto Velho-Cuiabá, km 48, 5 Feb 1983, Bilby et al. 33 (INPA); SE bank of Rio Jaci Paraná, before Jaci Paraná town, 9 Jul 1979, C.E. Calderón et al. 2986 (NY, US); Porto Velho, Guajará-Mirim, Estrada do Palheta, km 12, foot of Serra Parecis, 28 Jan 1983, Carreira 315 (INPA, MG); Itapuã de Oeste, Floresta Nacional de Jamari, 4 Dec 2011, Castro et al. 81 (herbarium unknown); 1 km from BR 364, ca. 1 km N of road to São Sebastião, 24 May 1984, Frame 171 (NY, U); Ji-Paraná, Reserva Biológica do Jaru, 125 m, 8 Jun 2015, Labiak 6250 (NY); between Jaci Paraná and Rio Madeira, 26 Jun 1968, Prance et al. 5218 (INPA, NY, U, US); basin of Rio Madeira, foothill of Serra dos Pacaás-Novos, 12 km NNE of Guajará-Mirim, 1 Aug 1968, Prance et al. 6672 (COL, INPA, NY, U); 8 km N of Porto Velho, basin of Rio Madeira, 7 Nov 1968, Prance et al. 8227 (F, INPA, NY, U); road to São Lorenço mines, N bank of Rio Madeira, 10 km above Mutumparaná, 25 Nov 1968, Prance et al. 8866 (NY, U, US); Porto Velho, Parque Nacional Mapinguari, trilha do parquet, 12-14 Dec 2013, Silveira 559, 596 (L, NY). Peru. Loreto: Prov. Requena, Oyo de Contaya, Serra del Divisor, between Contamana and Río Tapiche, 260 m, 10 Aug 2005, Uliana et al. 1342 (AMAZ, F, L). San Martín: Prov. Alto Amazonas, Yurimaguas-Tarapoto road, 15 km SW of Yurimaguas, 180 m, 10 Oct 1985, Gentry et al. 52203 (MO, U).

Notes.

We have named this species after Sir Ghillean Prance, who enabled the first author (PM) to undertake his first steps in the Amazonian world and assisted and taught him in a very kind and generous way.

Costus sprucei Maas and C. prancei sp. nov. closely resemble a third species, C. chartaceus Maas, which occurs in Amazonian Colombia, Ecuador, and Peru. They share many of the vegetative and floral features, but C. chartaceus Maas mostly has an unequally lobed ligule of 5-15 mm long, while that of the other two is truncate and 2-7 mm long. The essential difference can be found in the flower colour, which is pinkish-white in C. chartaceus (vs. pinkish-red in C. sprucei and yellow to orange in C. prancei ).

The two Peruvian collections (Gentry et al. 52203 and Uliana et al. 1342) look quite similar to this species and agree in most of the floral measurements, but the leaves are quite large for this species (i.e., 25-35 × 9-13 cm).

Figures

Figure 17. Costus prancei Maas & H. Maas Photo in habitat taken by Paul Maas at Serra do Moa, Acre, Brazil. Photo corresponds to Prance 12265 collected by G. T. Prance in 1971.

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.