Baccharis sect. Caulopterae, Candolle, 1836

Valtierra, María Victoria, Marchesi, Eduardo, Heiden, Gustavo & Bonifacino, José M., 2021, Baccharis rectialata (Compositae: Astereae): a new species of carqueja from Uruguay, Phytotaxa 478 (2), pp. 253-260 : 259

Key to the subshrubby species of Baccharis sect. Caulopterae s.s. occurring in Uruguay

1a. Wings width notably reduced towards the apex, basal width/ apical width> 2; involucres of pistillate capitula> 8.5 mm long ...... ................................................................................................................................................................................... B. riograndensis

1b. Wings width uniform throughout the plant or gradually reduced towards the apex, basal width/ apical width <2; involucres of pistillate capitula <8 mm long ...........................................................................................................................................................2

2a. Wings basal width 1.5–4.5 mm wide .................................................................................................................................................3

2b. Wings basal width 5.5–15 mm wide ..................................................................................................................................................4

3a. Wings margin notably sinuous, involucres of staminate capitula 4.5–6 mm long, involucres of pistillate capitula 5–7 mm long ..... ............................................................................................................................................................................................... B. crispa

3b. Wings margins straight or barely sinuous, involucres of staminate capitula 3.5–4 mm long, involucres of pistillate capitula 4.5–5.5 mm long........................................................................................................................................................................... B. rectialata

4a. Wings 10 – 18 mm wide (immediately below capitulescence); pistillate capitula with 89 to 164 florets; flowering from September to November .................................................................................................................................................................. B. jocheniana

4b. Wings 7.5–10 mm wide (immediately below capitulescence); pistillate capitula with 33 to 44 florets; flowering from February to May...................................................................................................................................................................................... B. trimera