Gingersrus Database Taxon ID 7289
Costus atlanticus 'Tropicais'
OLD NAME: Costus atlanticus 'Tropicais'
NEW NAME: Costus atlanticus 'Tropicais'
NAME CHANGE NOTES: Very popular cultivar from Brazil, published as Costus atlanticus, possible species or natural hybrid.
FULL SCIENTIFIC NAME:
STATUS : registered cultivar
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Below is a history of my acquisition of this cultivar and our attempts to classify it. It is now published as a new species Costus atlanticus (see under PID 7791) but there is still some doubt. I have seen hundreds of Inaturalist observations of this form but all of them have been from urban/suburban areas and none confirmed to be growing in the wild. There is still some question as to whether this form is a true species or simply a hybrid that has gained popularity in Brazil.
To Paul & Hiltje Maas: I received the spent inflo. cone today from the lady in Texas, but I am not sure I have enough of the plant to make a herbarium specimen that would be of any use to you. I did break it down and examined and measured the bracts, bracteoles and calyx, and took close-up photos that I could send. The plant does not appear to be mature as you would find in the wild - the sheaths only 8 mm in diameter. Ligules from 4-8 mm long, truncate, petioles 6-8 mm long and 3-4 mm wide, all glabrous and medium green in color. The leaves measured from 11-19 cm long and 4-8.5 cm wide, green and glabrous both side, with no indument along the costa or margins or elsewhere. Base cuneate to cordate, apex acute to shortly acuminate, acumen barely 1 mm long. The bracts are glabrous, coreaceous, ovate, margins entire, reddish green - deeper red in the covered parts, green callus about 8 mm long, and bracts measuring 3.3-3.5 cm long by 3.2 cm wide. Bracteoles dark red, boat shaped, glabrous, all 2.5 cm long and 0.5 cm wide. Calyxthe same dark red color, glabrous except for a few hairs at the junction with the ovary, 1.5 cm long and 0.8 cm wide. I do not have the flowers, but from the pictures they appear nearly pure white, corolla lobes and labellums, with just a tint of pink on the lateral lobes and yellow in the throat. The labellum lobes are not spread very wide. I am attaching the picture again for your convenience and ready reference.
Cultivar Registry Photo at http://www.gingersrus.com/Registry/Costus_Tropicais.jpg Cultivar published in the Heliconia Society Quarterly Bulletin, Vol. 20, No. 1, March, 2014.