Gonolobus, Michaux, 1803

Alvarado-Cárdenas, L. O. & Cerchiai, Alicia, 2022, A new species of Gonolobus (Apocynaceae, Asclepiadoideae, Gonolobineae) from Loja, Ecuador, Phytotaxa 575 (3), pp. 287-293 : 291

A taxonomic key for the determination of species of Gonolobus in Ecuador

1. Corolla diameter less than 1.5 cm .......................................................................................................................... Gonolobus campii

Corolla diameter larger than 2 cm ......................................................................................................................................................2

2. Dorsal anther appendages with bifurcated apex with arched and divergent lobes......................................... Gonolobus ophioglossa

Dorsal anther appendages with entire apex ........................................................................................................................................3

3. Pedicels 5–8 mm long; calyx lobes 5.5–6.2 mm long; corolla 2.8–3.1 cm in diameter................................ Gonolobus saraguranus

Pedicels over 3 cm long; calyx lobes 0.8–1.4 cm long; corolla 4–6 cm in diameter .........................................................................4

4. Stems with indumentum distributed more or less in 2 lines. Calyx lanceolate; corolla lobes lanceolate, and abaxially with short dense (0.03–0.1 mm) glandular hairs ....................................................................................................... Gonolobus albomarginatus

Stems with indumentum homogeneously distributed. Calyx ovate-lanceolate to elliptic-lanceolate; corolla lobes oblong, and abaxially glabrous....................................................................................................................................... Gonolobus rumihuilcanus