Costus acreanus 'El Gato'

The primary distinguishing character is the pendent inflorescence, otherwise found only in Costus bracteatus in Central America. Bracts are dark red, non-appendaged, and without fibrous margins. The bracts are distinctively concave in shape forming a cone somewhat similar to Costus scaber, but the flower has a broad, open labellum, mostly white, with a yellow throat and variable amounts of pink color on the labellum wings. The labellum wings are usually parallel to each other giving a flattened appearance to the flower. There are also noticable spots on the stems, most pronounced on the lower part of the stems.

Cultivar Registry Photo at http://www.gingersrus.com/Registry/Costus_ElGato.jpg Cultivar published in the Heliconia Society Quarterly Bulletin, Vol. 19, No. 4, December, 2013.

Since that 2007 visit to Ecuador, I have seen many other similar looking plants from the same region in Ecuador and also from Putumayo in southern Colombia. It fits best among currently described species as Costus acreanus, but may well be a new and undescribed species. At one point while Dr. Maas and I were working on the Revision to New World Costaceae, we drafted a proposed description for this form, and gave it the name of Costus pendens. Then after my January 2020 trip to Acre, Brazil we realized that the species Costus acreanus nearly always has a similar pendent or nodding inflorescence form and decided to include the "El Gato" plants in that species instead of describing a new species. It was only after seeing the results of the molecular phylogeny prepared at Cornell University that it has become apparent that this may indeed be an undescribed new species. The samples from southern Peru and Acre, Brazil were in a clade with Costus arabicus but the Costus 'El Gato' from Gualaquiza, Ecuador was in a completely separate lineage with the new species Costus convexus.

Below was our first draft of the proposed description:

Costus pendens Skinner & Maas, sp. nov.

Costus pendens can be recognized by its nodding (pendent?) inflorescence with dark red unappendaged bracts and white or pink open-labellum flowers, abaxially oriented. Type: D. Skinner R3079 (holo UC), Ecuador, Morona-Santiago, Gualaquiza, 1075 m, 7 June, 2007. (there are many other collections that could be chosen as the holotype, I chose this one simply because it was the first one I myself found. See list at the bottom of description for alternatives.)

Herb 2-4.5 m tall. Leaves: sheaths 22-28 mm diam, glabrous; ligule truncate to slightly lobed, 10-16 mm long, glabrous; petiole 23 mm long, glabrous; lamina elliptic to narrowly obovate, 40-55 cm long by 12-18 cm wide, usually glabrous both sides (rarely pubescent), base cuneate to somewhat cordate, apex long acuminate, medium green, sometimes purplish on the undersides. Inflorescence: nodding (pendent?), ovoid to cylindric, to 21 cm long by 6 cm in diameter, enlarging to 10 cm in fruit, terminating a leafy stem or rarely at the base on a nearly leafless stem; bracts unappendaged, margins entire, dark red or occasionally green on the exposed parts, with a conspicuous yellow-green nectar callus, concave in shape, 40-60 mm long by 25-32 mm wide; bracteole 24-38 mm long, unicarinate; calyx 14-22 mm long, deeply to shallowly lobed. Flowers: abaxially oriented, corolla lobes white, 68-87 mm long; labellum white with a pink blush, 90-105 mm long by 74-78 mm wide when spread; stamen 55-70 mm long. Capsule not measured.

Distribution - East of the Andes in southern Colombia, Ecuador, Peru and western Brazil.

Habitat & Ecology - In wet, tropical forests and disturbed areas at elevations of 200-1200 m. Flowering during rainy season.

IUCN Conservation Status - not analyzed

Vernacular names - no specific common name, generally cańa agria.

Etymology - Costus pendens inflorescences turn downward as the plants mature, as in Costus bracteatus and herbarium specimens can usually be identified by the bend in the sheath just below the base of the inflorescence. The specific epiphet pendens is chosen from the “pendent” inflorescence.

Other specimens examined. (LIST OTHER SPECIMENS, compile from lists beginning on next page)

Notes - Costus pendens has usually been determined in herbarium specimens as Costus laevis when the flowers were not seen, but this species produces abaxially oriented flowers - not the adaxially oriented flowers as in C. laevis (which is now to be known as Costus kuntzei). This species nearly always produces inflorecences terminal on a leafy shoot, but a few plants were seen in Parque Nacionál Manu in Peru with flowering at the base on a nearly leafless shoot. Young plants sometimes have dark purple undersides to the leaves. Mature plants often have reddish spots on the lower sheaths. The upper leaves often wrap tightly around the inflorescence.

Further research and additional sampling of the molecular data are needed before a final decision can be made about this possible new species.

HORTICULTURAL NOTES:
The original Costus 'El Gato' has had limited distribution and is found in a few botanical gardens. There is also a plant at the National Tropical Botanical Garden that originated in Colombia that has this same form.

ACCESSIONS:Click links (if any) to see details of individual collections. R3006- R3060- R3079- R3080-

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