Clematis, Linnaeus, 1753

Piovesani, Willian Souza, Ferreira, Priscila Porto Alegre & Seger, Guilherme Dubal Dos Santos, 2024, Clematis serrana (Ranunculaceae), a new endemic species to the Atlantic Forest highlands in Southern Brazil, Phytotaxa 660 (2), pp. 149-160 : 157

Key to the species of Clematis in the Atlantic Forest Biome based on pistillate flowers and fruits

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. Pistillate flowers with more than 35 carpels.................................................................................................................. C. denticulata

4. Pistillate flowers with up to 35 carpels...............................................................................................................................................5

5. Achenes fusiform; leaflet blades ovate, margin entire, apex long-acuminate................................................................. C. brasiliana

5. Achenes elliptic or ovate; leaflet blades ovate or elliptic, margin entire or toothed, apex straight or acuminate..............................6

6. Inflorescences with 6–18 flowers; leaflet blade margin toothed......................................................................................... C. serrana

6. Inflorescences with 25–210 flowers; leaflet blade margin entire or toothed in young leaves ...........................................................7

7. Mature leaves pinnate with 5 leaflets; leaflet blade margin entire; indumentum white...................................................... C. integra

7. Mature leaves bipinnate with more than 5 leaflets; leaflet blade margin entire or toothed in young leaves; indumentum yellow ..... ............................................................................................................................................................................................ C. discolor