Key to the species of the Scyphostelma harlingii group

1. Corolla glabrous, gynostegial corona flat, spreading, ± appressed to corolla; peduncles <10 mm long.... 2

– Corolla with indumentum, gynostegial corona suberect or erect and appressed to gynostegium or gynostegial stipe; peduncles> 10 mm long...... 3

2. Leaves ovate to ovate-lanceolate; staminal corona lobes 1.4–1.8 mm long, rounded rectangular, only basally fused................... 1. S. bolivianum

– Leaves narrowly lanceolate; gynostegial corona fused to a collar-like structure......... 2. S. erikseniae

3. Leaves, if present at all, linear-lanceolate, to 10 mm long; staminal corona lobes deltate.. 6. S. solomonii

– Leaves lanceolate, 15–45 mm long; staminal corona lobes not deltate........................... 4

4. Staminal corona lobes plane, rectangular with rounded shoulders, suberect with a vertical wave, basally fused and forming a bowl-like structure..... 3. S. gracile

– Staminal corona lobes 3-dimensional, spreading, reflexed, laterally attached to a gynostegial stipe... 5

5. Corona about as long (high) as gynostegium, staminal corona lobes ± appressed to gynostegial stipe................................... 4. S. harlingii

– Corona only c. 1/2 as long (high) as gynostegium, free staminal corona lobes much protruding, each spreading horizontally for c. 0.8 mm with margins approaching at lower edges........ 5. S. rotorum

Taxonomic descriptions