Comparison of Costus lasius, scaber, sprucei, and chartaceous.
From Maas, Flora Neotropica, Monograph #8
C. lasius C. scaber C. sprucei C. chartaceus
Sheath diameter 3-8 mm 5-20 mm 5-13 mm 6-10 mm
Sheath indument hirsute glabrous to puberulous strigose to villose glabrescent
Leaf upper indument hirsute to glabrous glabrous to puberulous glabrous, villose, hirsute, strigose glabrous to villose
Leaf lower indument hirsute glabrous to puberulous strigose to villose glabrous to villose
Bract texture coriaceous (rarely chartaceous) coriaceous chartaceous (rarely coriaceous) chartaceous
Bracteole length 8-12 mm 9-12 mm 8-11 mm 15-18 mm
Calyx length 3-5 mm 3-7 mm 6-8 mm 9-11 mm