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

Gingersrus Database Taxon ID 4602

Costus zamoranus


OLD NAME: Costus zamoranus

NEW NAME: Costus zamoranus

NAME CHANGE NOTES:

FULL SCIENTIFIC NAME: Costus zamoranus Steyerm.

STATUS : accepted

CONTINENT: Neotropical

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

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

SYNONYMS:


BOTANICAL NOTES:
Costus zamoranus is an accepted species of neotropical Costus described by Julian Alfred Steyermark in 1964 based upon his 1943 collection 54664 at Tambo Valladolid along the Rio Valladolid in Zamora-Chinchipe, Ecuador. Steyermark is best known for his exploration of the "Lost World" of the guiana shield region in eastern Venezuela. His original description and accordingly Paul Maas' description in his 1972 monograph had very few destails of this species, especially its flowers. There were no photos of the living plants - only the dried herbarium specimens - and no assurance that they were correctly identified. Dr. Maas wrote:
"The position of this species is rather uncertain as nothing is known of its floral structure. It seems closest to Cotus amazonicus, from which it can only be distinguished by its calyx."

In February 2015, I traveled to southern Ecuador to learn more about Costus zamoranus . The only way to be sure I found the right plant was to go to the remote type location in the Mayo-Chinchipe region at the town of Valladolid. There was still a good forest patch across the river from the town and thanks to the help of Marco Jiménez - Leon and his father Marco Jimenez, we found it there and a few other places as well. I have prepared a thumbnail sheet with the photos at Valladolid at http://www.gingersrus.com/images/R3324

After leaving Valladolid we traveled along the road toward the community of Tapala. Most of this area was deforested but there were a few patches of forest and there we found more Costus zamoranus, some flowering at the base on separate leafless shoots and some flowering at the top of leafy shoots. It is uncertain whether all these plants are C. zamoranus or if they are a form of the newly reinterpreted Costus laevis. Photos of these are at http://www.gingersrus.com/images/R3326

The third place we saw this species was east of Palanda near the Rio Numbala at 925 meters. Based on our observations, this species was only found in shady areas, usually with a coarse sand base. The flowers were variable but at this location, were the most beautiful ones, a deep garnet color. My thumbnail sheet for this example of C. zamoranus can be found at http://www.gingersrus.com/images/P4602

Perhaps the most interesting plant we found was this one, which fits perfectly with the description of C. zamoranus but was distinctively different from the plant found in the type local near Valladolid. It was growing in very heavy sticky grey soil of the Cord. del Condor. The bracts have a distinctive reddish margin and the nectar callus on the bracts is dark red in color. The flowers were more tubular in shape than the type, and this plant was much more clearly distinguishable from it's closest species - C. amazonicus or C. laevis. My thumbnail sheet for these plants is found at http://www.gingersrus.com/images/R3336

In the Tundayme area of the Cord. del Condor at 1150 meters we found two plants, one flowering the normal basal inflorescence and one terminal, both of which were totally consistent with the type for the species at Valladolid. As with most Costus species, it seems this one also has the potential to flower both ways. Thumbnail sheet at http://www.gingersrus.com/images/R3341

El Oso Road - We did find one plant that was closer to the type but located in a region far to the north which helped me better understand the range of this species. It was clear that this species only grows in the shade of forested areas, which are quickly disappearing from southeastern Ecuador. One of my objectives was to determine the threat status so I could update my assessment of this species on the IUCN Red List. Here is a short thumbnail with a few images at this location. http://www.gingersrus.com/images/P4602-2

In 2022 I returned to Ecuador and visited areas east of the Andes in Pastaza and in Napo. Here to my surprise I found many more populations of this species - expecially in the Narupa region north of Tena. Photos of these observations can be found on the Inaturalist link above.

Costus zamoranus was assessed as "Vulnerable" on the IUCN Red List in 1997. I completed an updated assessment in 2014 and maintained its status Vulnerable, but this mostly based on incomplete information. The assessment with further details can be found at http://www.iucnredlist.org/details/45121/0. It is endemic to Ecuador, but clearly now it is much more common than was thought, and I believe when it is reevaluated at IUCN Red List, it will be found to be of "Least Concern". It flowers during the rainy season and perhaps throughout the year.

DNA was extracted from my collection at the type locality (R3324) and was found to be in a separate clade close to Costus asplundii.

HORTICULTURAL NOTES:
Based on information at the Botanic Gardens Conservation International (BGCI) this species is in ex situ cultivation at only 2 botanical gardens world wide. I have found this species to be somewhat difficult to grow in my garden and greenhouses at Le Jardín Ombragé and I have not yet brought it to flower in cutlivation.

ACCESSIONS:Click links (if any) to see details of individual collections. R3324- R3325- R3326- R3328- R3336- R3340- R3341- R3527- R3528- R3529-


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Photos (if available) of Taxon ID 4602
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Costus zamoranus, photo by Skinner in habitat, Rio Numbala, Chinchipe valley, Ecuador - Click to see full sized image
Photo# 343 Accession# R0
Costus zamoranus, photo by Skinner in habitat, Rio Numbala, Chinchipe valley, Ecuador


Costus zamoranus type specimen - Click to see full sized image
Photo# 552 Accession# R0
Costus zamoranus type specimen


Costus zamoranus type specimen - Click to see full sized image
Photo# 553 Accession# R0
Costus zamoranus type specimen


Costus zamoranus type specimen - Click to see full sized image
Photo# 554 Accession# R0
Costus zamoranus type specimen


Costus zamoranus type specimen - Click to see full sized image
Photo# 555 Accession# R0
Costus zamoranus type specimen


Costus zamoranus, Skinner R3326, along Tapalo Road near type locality, Zamora-Chinchipe, Ecuador - Click to see full sized image
Photo# 344 Accession# R3326
Costus zamoranus, Skinner R3326, along Tapalo Road near type locality, Zamora-Chinchipe, Ecuador