Key to Wisconsin Lobelia

• 1a.Flowers (including hypanthium) 2.5–4.5 cm long; corolla tube with window-like slits near the base on each side; anther tube 3.5—5.5 mm long 2

• 1b.Flowers 0.5–1.5 cm long (to 2.2 mm in L. dortmanna); corolla tube lacking slits on the sides; anther tube 1–2 mm long 3

• 2a.Corolla bright red (rarely white); filament tube 2.4–3.3 cm long, exceeding the corolla tube; calyx lobes glabrous, lacking auricles L. cardinalis

• 2b.Corolla blue or purplish-blue, sometimes with white, longitudinal stripes (rarely completely white); filament tube 1.2–1.5 cm long; calyx lobes bristly-ciliate, conspicuously auriculate L. siphilitica

• 3a.Stems scapose or with a few small bracts, the leaves all basal, usually submersed, subterete, consisting of 2 hollow tubes; flowers 12–22 mm long L. dortmanna

• 3b.Stems leafy, the leaves rarely submersed, flat, not tubular in construction; flowers 7–13 mm long 4

• 4a.Middle and upper leaves ovate to oblong, lanceolate, elliptic, obovate, or oblanceolate, 4–33 mm wide; pedicels with paired bracteoles at or near the base; lower lip of the corolla bearded at the base within L. kalmii

• 4b.Flowers (open, showy ones) along the upper 1/3–2/3 of the stem, sessile in the axil of a slightly smaller, upper leaf (bract), forming a false spike often 3–24 cm long; leaves and bracts ± suborbicular, sessile and cordate-clasping; style straight; pores of the capsules submedian; slender annual 5

• 5a.Hypanthium nearly as long as the corolla, rapidly inflating after anthesis and completely including the capsule; stems hirsute, at least below, many of the hairs 0.5–1 mm long (upper stems strigose to subglabrous); corolla white with bluish lobes, 3–5 (–6) mm long L. inflata

• 5b.Hypanthium shorter than the corolla, slightly inflated in fruit, the capsule ca. 1/4–1/2 exserted; stems hirtellous toward the base, the hairs ≤ 0.5 mm long (mostly glabrous or glabrate above); corolla blue (mostly light blue), 4–10 mm long L. spicata