Gingersrus Database Taxon ID 7779
OLD NAME: Costus comosus - hort. form wild
NEW NAME: Costus comosus
NAME CHANGE NOTES: form in the wild similar to cultivated form
FULL SCIENTIFIC NAME:
STATUS : distinct form
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.)
This form is quite different from other examples of Costus comosus, having more obtuse bract appendages and a larger, showier inflorescence often growing at maturity to 30 cm long or more. Normally this form produces terminal inflorescences on tall leafy stems but occasionally it flowers at the base on leafless or nearly leafless shoots. It is best known for the cultivated plant known as "red tower ginger" or sometimes incorrectly listed by the species name Costus barbatus. This form is found in the southernmost part of the range for Costus comosus, with known wild collections and observations in Bolivia and Peru. I have seen it growing in the wild in the Villa Tunari area of province Cochabamba in Bolivia and also in department JunÃn in Peru. It is quite similar to a sp. nov. that has been proposed by Paul Maas to be called Costus cochabambae, differing by the color or the bracts and the length of the ligule. It is also similar to the species Dr. Maas described in 1972 as Costus quasi-appendiculatus, which he is now proposing to merge as a synonym with his very-much-polymorphic complex of Costus comosus.
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. DNA has been extracted from samples of this form and the others. and it has been found to be in a completely separate lineage from the other forms, in a well supported separate clade. Additional sampling is planned, and I believe will support the establishment of a separate new species.
Additional photos and description of the cultivated plants in this form may be found at http://www.gingersrus.com/DataSheet.php?PID=7586.
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