This page contains photos and description of a species, form or cultivar of Costaceae.

Gingersrus Database Taxon ID 4862

Costus krukovii

OLD NAME: Costus amazonicus subsp. krukovii

NEW NAME: Costus krukovii

NAME CHANGE NOTES: Elimination of the subspecies designation, this will be Costus krukovii in the proposed revision.

FULL SCIENTIFIC NAME: Costus krukovii (Maas) Maas & H.Maas

STATUS : stat. nov.

CONTINENT: Neotropical

FIELD OBSERVATIONS:(If field observations are available, you can click on the link to open in a new window.)

PHOTOS:(If photos are available, you can click on the link to open in a new window.)

- Costus amazonicus (Loes.) J.F.Macbr. subsp. krukovii Maas (1972)

Costus krukovii is proposed for publication in 2022 to separate the two subspecies of Costus amazonicus as discrete species. It is distinguished from Costus amazonicus by the bracts being entire (not fibrous) and having the apex slightly pungent or slightly recurved instead of rounded. It usually flowers only from separate leafless or nearly leafless shoots at the base whereas C. amazonicus can flower either way. I have found that this species can usually be identified by sense of feel, squeezing the sheaths near the base and feeling a soft spongy stem instead of firm and hard. It is found in Amazonian parts of Colombia, Ecuador, Peru and Brazil, where it can be found in flower year round.

The type specimen, still listed as Costus amazonicus (Loes.) J.F. Macbr.: subsp. krukovii Maas was collected in 1934 by Krukoff No. 7165 from Brazil, Amazonas, Humaita. Basin of Rio Madeira Municipality Humayata, on plateau between Rio Livramento and Rio Ipixuna. 7.51 S, 63.02 W. Other specimens det by Maas at Herbario do Jardim Botanico do Rio de Janeiro. Prance No. 3445, Nov. 1966, Road Humaita to Porto Velho, km 10. Low forest on terra firme. 1.5 m tall, corolla yellow with red streaks. Both these specimens show inflorescence on a separate basal leafless shoot.

I have not seen this species in flower yet in the wild, but have seen it with older inflorescences, growing at locations in Peru and in Brazil as indicated in the Inaturalist observations at the link above. A partial phylogeny was completed by Eugenio Valderrama and his associates in the Chelsea Specht Lab at Cornell University and was published in the journal Frontiers in Plant Science in September 2022. Tissue samples from 2 of the collections in Brazil were included and show this species to be well separated, in a separate well-supported clade from Costus amazonicus.

This species is in cultivation in several botanical gardens but not widely distributed.

The origin of the cultivated plants is specimen at Lyon #82-1252 - Collected by the late Ray Baker with Helen Kennedy in Ecuador, 33 km south of Rio Aguarico on Coca-Lago Agrio Road at elevation of 350 m. K. Nagata #2824. Ray Baker describes as "Stems 70-80 cm tall, red, 2 cm diameter at base, leafy only at apex. Leaaf blades broadly obovate, the veins prominent, sheaths inflated on stem. Infl. separate from leafy stems, on red peduncles 25 cm ht., ovoid, 10 cm long, 5 cm diameter, bracts green. Corolla white, 6.5 cm long, staminodes yellowish with oragne at apex, the lip yellow. "

His collection is also found at the Smithsonian Greenhouses, accession USBRG 1994-679. I noticed the soft, spongy-hollow feeling stems when I first saw it there in 2001 and at Waimea Arbroretum, No. 82P806, in 2006.

ACCESSIONS:Click links (if any) to see details of individual collections. R2262- R2654- R2936- R3432- R3471- R3472- R3475- R3480- R3481- R3484- R3536- R3541-

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Photos (if available) of Taxon ID 4862
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Costus krukovii, photo from Maas, by Robin Foster, 7676 RF.jpg - Click to see full sized image
Photo# 235 Accession# R0
Costus krukovii, photo from Maas, by Robin Foster, 7676 RF.jpg

Costus krukovii, photo from Maas, by Robin Foster, 7677 RF.jpg - Click to see full sized image
Photo# 236 Accession# R0
Costus krukovii, photo from Maas, by Robin Foster, 7677 RF.jpg

Costus krukovii type specimen - Click to see full sized image
Photo# 494 Accession# R0
Costus krukovii type specimen