Key to the species of Bolusiella

1. Leaves not deeply sulcate on upper surface 2
1a Leaves deeply sulcate on upper surface 5
2. Pouch-like outgrowth at the base of the lower sepals and floral bract as long as the flower 3
2a Base of the lower sepals without outgrowth and floral bract strictly smaller than the flower 4
3. Base of the inflorescence straight, spur 1.2 mm or longer Bolusiella maudiae
3a Base of the inflorescence fractiflex, spur up to 1.1 mm Bolusiella fractiilexa
4. Leaves with rounded apex Bolusiella zenkeri
4a Leaves with acute apex Bolusiella talbotii
5. Spur at right angle or partly curved under the lip, cylindrical, > 1mm Bolusiella iridiiolia
5a Spur in the same plane as the lip, conical, < 1mm long B. iridiiolia subsp. picea
6. B. iridiiolia subsp. iridiiolia

WCSP (2017). 'World Checklist of Selected Plant Families. 24.02-2017;