Plant Catalog › Lobelia siphilitica (Blue Cardinal Flower) Lobelia siphilitica (Blue Cardinal Flower) $0.00 Blooms: SummerH: 2-3' W: 18-24"Color: Blue Shades, Green Shades Add To Cart Added! Blooms: SummerH: 2-3' W: 18-24"Color: Blue Shades, Green Shades