Costus spiralis - Terminal form and Basal form
Found at Cristalino in Mato Grosso, Brazil
Click thumbnail to open full size image.

Click to see 01Costus_spiralis-terminal-Airport2-R.JPG
The first plant to greet me when I arrived at Alta Floresta airport was Costus spiralis.
Click to see 02Costus_spiralis-terminal-Airport1-R.JPG
As I learned later, this is the terminal flowering form, but there is an entirely different form (probably should be formally described as a separate variety) that typically flowers at the base of the plant.
Click to see 03Costus_spiralis-terminal-RockyOutcrop-R.JPG
In its natural habitat at Cristalino, I only found this terminal flowering form in open sunny areas growing on large rocky outcrops.
Click to see 04Costus_spiralis-terminal-SecretGarden1-R.JPG
They call this area the "Secret Garden", located on a rocky outcrop at the end of one of the trails.
Click to see 05Costus_spiralis-basal-habitat-R.JPG
The other, basal flowering form was not found in the rocky areas, only in the lower, wetter areas of the forest floor.
Click to see 06Costus_spiralis-basal-InFlower-R.JPG
The "basal" form flowers from separate leafless stems and is a distinctively different plant from the terminal flowering form - not simply a species that flowers both ways.
Click to see 07Costus_spiralis-terminal-SecretGarden4-R.JPG
This huge patch of the terminal flowering form is growing on a rocky outcrop in the Secret Garden. One of the guides told me they were researching frogs to find out where they go in the dry season, and when they removed some boulders they found cool moist caverns underneath, and this Costus had masses of roots as long as 2 meters growing down under the rocks.
Click to see 08Costus_spiralis-terminal-SecretGarden2-R.JPG
The inflorescence of the terminal form usually has leafy appendages growing from some of the bracts.
Click to see 09Costus_spiralis-terminal-SecretGarden3-R.JPG
This photo of the termial flower shows the leafy appendages clearly.
Click to see 10Costus_spiralis-basal-InFlower2-R.JPG
And here is the basal flower, whch did not have leafy appendages to the bracts.
Click to see 11Costus_spiralis-terminal-SecretGarden5-R.JPG
Another terminal inflorescence here. Other than the leafy appendages, they were nearly identical.
Click to see 12Costus_spiralis-basal-flower2-R.JPG
Basal flower.
Click to see 13Costus_spiralis-basal-flower1-R.JPG
Basal flower showing the openning in the labellum with the stamen equal to labellum.
Click to see 14Costus_spiralis-terminal-Ligule-R.JPG
The terminal form has a cordate leaf base with virtually no petiole and a very short ligule.
Click to see 15Costus_spiralis-basal-Ligule-R.JPG
The basal flowering form has a very long petiole and a longer ligule than the terminal flowering form.
Click to see 16Costus_spiralis-terminal-bract-bracteole-calyx-R.JPG
Terminal flowering form - bract, bracteole and calyx.
Click to see 17Costus_spiralis-terminal-bracteole-calyx-R.JPG
Termnal flowering form - bracteole and calyx
Click to see 18Costus_spiralis-basal-bract-R.JPG
Basal flowering form - bract
Click to see 19Costus_spiralis-basal-CalyxBracteole-R.JPG
Basal flowering form bracteole and calyx. The calyx here might be a little shorter but otherwise the two forms are identical.
Click to see 20Costus_spiralis-basal-CorollaLobes-R.JPG
Corolla lobes from basal form
Click to see 21Costus_spiralis-basal-stamen-R.JPG
Stamen from basal form.
Images Copyright 2012 - Dave Skinner