Lobelia — 8 species

Lobelia is a diverse genus ranging from low-growing edging annuals like 'Crystal Palace' and Edging Lobelia to tall native perennials such as Lobelia cardinalis (cardinal flower) and Lobelia siphilitica (great blue lobelia). Compact varieties thrive in full sun to part shade; taller perennial species prefer consistently moist to wet soil and tolerate light shade, especially in warmer regions. Cardinal flower in particular requires reliably moist soil and never tolerates drought. All Lobelia species are toxic to cats and dogs, containing lobeline alkaloids that cause vomiting, excessive salivation, and heart rhythm disturbances.