Key to the species of Clematis in the Atlantic Forest Biome based on staminate flowers

1. Mature leaves trifoliolate.............................................................................................................................................. C. bonariensis

1. Mature leaves pinnate, bipinnate, or tripinnate ..................................................................................................................................2

2. Mature leaves tripinnate; endemic to Itatiaia, Serra da Mantiqueira............................................................................ C. ulbrichiana

2. Mature leaves pinnate or bipinnate.....................................................................................................................................................3

3. Flowers bisexual (perfect); leaflet blades linear-lanceolate (rare ovate), margin entire; highland grasslands............... C. campestris

3. Flowers unisexual, with staminodes or pistillodes (sometimes staminate inflorescences with perfect flowers); leaflet blades of other shapes; forests ...........................................................................................................................................................................4

4. Inflorescences with up to 20 flowers..................................................................................................................................................5

4. Inflorescences with more than 20 flowers..........................................................................................................................................6

5. Staminate partial inflorescences in normal cymes ........................................................................................................ C. denticulata

5. Staminate partial inflorescences in compressed cymes (false whorls)................................................................................ C. serrana

6. Staminate partial inflorescences in normal cymes; mature leaves pinnate with 5 leaflets.................................................. C. integra

6. Staminate partial inflorescences in compressed cymes (false whorls); mature leaves bipinnate with more than 5 leaflets..............7

7. Leaflet blades ovate with apex long-acuminate; indumentum white .............................................................................. C. brasiliana

7. Leaflet blades elliptic with apex acuminate; indumentum yellow ..................................................................................... C. discolor