Prosopanche, de Bary, 1868

Machado, Ricardo Ferreira & Queiroz, Luciano Paganucci De, 2012, A new species of Prosopanche (Hydnoraceae) from northeastern Brazil, Phytotaxa 75 (1), pp. 58-64 : 62

Key to the species of Prosopanche

1. Rhizome (4–)5(–6)-angled; flowers with perigonium lobes 32–70 × 24–50 mm, synandrium 19–40 × 11–25 mm ... 2

- Rhizome 3–4-angled; flowers with perigonium lobes 18–55 × 4–20 mm, synandrium 9–25 × 4–8 mm ................... 3

2. Flowers in fascicles; perigonium lobes 32–56 × 24–36 mm; synandrium 19–26 × 11–16 mm; Costa Rica................ ............................................................................................................................................. Prosopanche costaricensis

- Flowers single; perigonium lobes 60–70 × 30–50mm; synandrium 30–40 × 23–25 mm; southern South America ( Argentina, Paraguay) and Peru............................................................................................... Prosopanche americana

3. Anthers with 5–8 thecae; staminodes split in two oblongoid bodies; fruit globose or ellipsoid; northeastern Brazil... .............................................................................................................................................. Prosopanche caatingicola

- Anthers with 20–30 thecae; staminodes entire or bilobed; fruit obovoid or pyriform; southern South America (western Brazil, Argentina, Paraguay and Bolivia........................................................................... Prosopanche bonacinai