What’s a dichotomous key?
Help
Verbena
See list of 8 species in this genusReference: Perry (1933).
-
1a. Leaf blades 1- or 2-times pinnatifid, cleft into 3–5 segments, or with deep sinuses producing lobe-like teeth [Fig. 925]
-
2a. Floral bracts 8–15 mm long; calyx 3–4 mm long; spikes 2–10 (–15) × (0.6–) 1–1.5 (–2) cm in fruit
-
2b. Floral bracts ca. 1–1.3 mm long; calyx 2–2.5 mm long; spikes (7–) 10–25 ×0.2–0.5 cm in fruit
-
-
-
3a. Spikes solitary or less frequently in trios at the tips of the stem and branches [Fig. 926]
-
4a. Leaf blades slightly tapered to the base, sometimes with an broad, ill-defined, petiole-like base; spikes obloid to cylindric, mostly 3–7.5 times as long as wide
-
4b. Leaf blades conspicuously tapered and/or very narrow at the base, often with a short, but evident, petiole; spikes cylindric to narrow-cylindric, (6.5–) 7.5 or more times as long as wide
-
5a. Stems sparsely strigillose; leaf blades linear or narrow-oblong to lanceolate or narrow-spatulate, the primary ones 3–15 mm wide; limb of corolla 4–6 mm wide
-
5b. Stems hirsute, often densely so; leaf blades elliptic to ovate or suborbicular [Fig. 926], 15–50 (–60) mm wide; limb of corolla 7–9 mm wide
-
-
-
3b. Spikes few to numerous, in panicles near the apex of the plant [Fig. 927]
-
6a. Leaves sessile and clasping the stem; spikes (0.6–)2–5.5 cm long in fruit; floral bracts 3-4 mm long
-
6b. Leaves petiolate, not clasping; spikes 3–30 cm long in fruit; floral bracts 0.5--2 mm long
-
7a. Corolla white, the limb usually 2–2.5 mm wide; flowering spikes slender, 2–4 (–5) mm wide, relatively less crowded, the flowers not contiguous [Fig. 927]; styles mostly 0.4–0.6 mm long
-
7b. Corolla blue, the limb 2.5–4.5 mm wide; flowering spikes thicker, mostly (5–) 6–8 mm wide, with crowded and contiguous flowers; styles mostly 1–1.5 mm long
-
-
-
Show photos of:
Each photo represents one species in this genus.