Plant Datasheet for Costus spicatus

Maas compares those three species in a chart, reproduced in a table on a separate page at http://www.gingersrus.com/botanical/CompareThree.htm .

The type is from the island of Martinique, and the species is distributed in the Caribbean islands of Hispanola and the Lesser Antilles. It is not known from mainland Central or South America. GBIF records reflect a number of collections from Mexico (none of which were determined by Paul Maas) which are no doubt errors.

ACCESSION NOTES:
R3028 is Smithsonian USBRG#2002-127 which was collected by John Kress in Hispaniola and tagged as Costus cylindricus. I have grown this plant out and studied it carefully and it fits Maas' description of C. spicatus. This collection has been vouchered at the UC Berkeley, Jepsen Herbarium, UC2045801.

OBSERVATION NOTES:

Indian River, Portsmouth, Dominica, Latitude 15.57087, Longitude -61.44986, at 40 meters elevation.

Layou River, Saint Joseph Parish, Dominica, Latitude 15.4134, Longitude -61.395, at 70 meters elevation.

Fond Cani, Dominica, Latitude 15.31695, Longitude -61.3469, at 160 meters elevation.

Castle Bruce, Saint David Parish, Dominica, Latitude 15.41865, Longitude -61.27842, at 63 meters elevation.

GINGERSRUS CATALOG LISTING:
Do a Google search for photos of Costus spicatus and you will find lots of web pages with photos, but they are all photos of Costus scaber. The true Costus spicatus is very similar, but the bracts are more greenish and there are subtle differences in the flower parts, such as the length of the calyx and bracteole. Also, the true Costus spicatus has a very limited range, native only to the Carribean islands of Hispanola.

A few years ago I acquired a plant tagged as Costus cylindricus, that was collected in Hispanola. Paul Maas, who wrote the monograph on Costus in the 1970's, listed the species name "Costus cylindricus" as an obsolete synonym for Costus spicatus. The plant finally bloomed in my greenhouse and I am now convinced that this is the true species Costus spicatus.

The flowers of this plant are larger in proportion to the bracts and the labellum is a soft yellow color. Otherwise the plant is pretty non-descript, with typical Costus green stems and leaves. I have not yet tested this plant for hardiness and frankly have no idea whether it will turn out to be hardy like its namesake Costus scaber-spicatus, but the plant is a fairly vigorous grower, and a bit taller (6-7 feet) than Costus scaber. It seems to prefer a fairly sunny location in my greenhouse but has not been tested outdoors yet.