I am not sure if this is the best key: 2. Corolla tubes 4–6(–7) mm, 1.5–2 mm longer than the calyces; distal stems, peduncles, and calyces stipitate-glandular; spikes 8–30 mm in fruit; floral bracts 2.1–2.8 mm; nutlets 1.5–1.9 mm; basal and midstem leaves oblong-lanceolate to oblong-oblanceolate ............. Verbena bonariensis 2. Corolla tubes 2.5–4 mm, 0–0.5 mm longer than the calyces; stems, peduncles, and calyces eglandular; spikes 6–55 mm in fruit; floral bracts 3–4 mm; nutlets 1–1.2 (–1.4) mm; basal and midstem leaves ovate to ovate-lanceolate, oblong-elliptic, or obovate .............. Verbena incompta Nesom, G.L. 2010. Taxonomic notes on Verbena bonariensis (Verbenaceae) and related species in the USA. Phytoneuron 2010-12: 1–16. 13 May 2010.