Plant Datasheet for Costus guanaiensis var. tarmicus

Maas places the distribution as mainly in northwestern South America (including Huanuco and Junin in Peru) and possibly Mexico. Most collections that have been determined by him to be this variety are from western Ecuador, Esmeraldas and Pinchincha.

The form attributed to this variety that is usually found in cultivation is the one with the inflated basal ligules, with bract appendages usually curled down, and with mostly yellow flowers vs. the white flowers of var. guanaiensis.

I have seen this form many places in cultivation but only in western Ecuador in the wild. Two of the herbarium specimens in Quito Ecuador for this variety were collected in Esmeraldas, and Guayas, determined by Maas. Also there is a specimen at Waimea 74S2037 - Received seed from Plowman 1974, collected Ecuador, Pichincha Rd., Aloag-Santo Domingo, Tahdape, Alt. 2000 ft. Det'd by Paul Maas Sept 1981, also by Plowman and by "Utrecht" 1977. Note that Waimea also has a collection 80P661 from Gardner Waters of CA, raised from seed from the Ron Hurov Nursery in Hawaii.

However, the form found in Peru, where the original type was called Costus tarmicus, is visually different from the Ecuadorian plants and does not have the inflated ligules. These are on a separate page atPID7605

In Caluma, Bolívar, Ecuador I saw two different forms of var. tarmicus - the more common was a white flowering form, seen several places at and above 400 meters. The yellow flowering form was seen below 400 meters.
I found one plant in the yellow flowering form at lower altitude, at the base of Cerro Semama. Thumbnail sheet at
http://www.gingersrus.com/images/R3346

This was the most common Costus in the Caluma area, but was usually found in a white flowering form instead of the yellow flowering plant that is most often found in cultivation. Here is my thumbnail sheet for this one:
http://www.gingersrus.com/images/R3344

UPDATE: In November 2016 I traveled to central Peru in the area around Tingo Maria, Dept. Huanuco to visit the type locality of three species: Costus laevis, Costus scaber and Dimerocostus argenteus, which were collected and described over 200 years ago by Hipólito Ruiz. At the poblado Cuchero, where Ruiz had stayed for several months I found a plant that best fits the currently described species Costus guanaiensis var. tarmicus, and has sometimes been attributed to an undescribed species Costus aff. claviger. The plant found at Cuchero matches very closely to the written description by Ruiz of a plant he named as Costus laevis. The entire situation is further complicated by the fact that the holotype of his Costus laevis is yet a different plant, also found in this region, that most closely fits to the currently described Costus spiralis. I suspect that the Cuchero plant is the same plant form as was collected, named and described as Costus tarmicus, from La Merced in Junin Dept. of Peru. Further research is needed to sort all this out, but the report of my findings is published in the December 2016 quarterly Bulletin of the Heliconia Society International. SeePID 7605

ACCESSION NOTES:
R2931 is from seeds received, origin unknown, from Marcos Sobroso. It is glabrous on both sides of leaves.

R3012 from Waimea did not survive.

R3344 white flowering form from Caluma. R3346 yellow flowering form from Caluma

OBSERVATION NOTES:

Road to Cueva Pumahuassi, Leoncio Prado Province, Peru, Latitude -9.195271, Longitude -75.955442, at 700 meters elevation.

Trail to Catarata San Miguel, Huanuco, Peru, Latitude -9.493, Longitude -75.902, at 1200 meters elevation.

Rio Repente, Cayumba, Leoncio Prado Province, Peru, Latitude -9.5, Longitude -75.975, at 830 meters elevation.

Santa Rita Sur, Huanuco, Peru, Latitude -9.6082, Longitude -75.8702, at 900 meters elevation.

San Juan de Cocheros, Huanuco, Peru, Latitude -9.54053, Longitude -75.93828, at 1275 meters elevation.

GINGERSRUS CATALOG LISTING:
In his 1972 monograph on Costus in Flora Neotropica, Paul Maas described 4 varieties of the species Costus guanaiensis (var. guanaiensis, macrostrobilus, tarmicus and asplundii). In his 1977 update, he moved var. asplundii to its own species (C. asplundii) but retained the other three as varieties of Costus guanaiensis. The only difference in the official descriptions is the presence or absense and types of hairs on the leaves. After seeing many hundreds of Costus guanaiensis plants both in cultivation and in nature, I am really confused, as there seems to be no clear distinction in the hairiness of these varieties. At any rate, the variety that is usually listed as var. tarmicus is quite distinct from the others by the raised ligules on the stems, the yellow flowers, and the shape of the foliacious appendages to the bracts. These characters have been consistent in plants I found throughout Ecuador and in botanical gardens in Hawaii.

Okay, enough of the botany.... in cultivation this variety makes for a rather attractive ornamental plant. When not in flower the stems have interest in themselves, and when in flower the plant is quite beautiful. I have only tried growing it in my greenhouse, and I doubt that it would be winter hardy in frost prone ateas. It can grow to be about 8 feet tall under the right conditions, and probably will not bloom unless it is allowed to do so. It seems to prefer a position in part sun with typical moist, but well drained organic soil.