Additional blue flowering plants suited to the warmer climates of the tropics, subtropics and warm temperate climates include:

Agapanthus (Agapanthus praecox)
Brazilian Potato Tree (Solanum wrightii)
Cat’s Whiskers (Orthosiphon aristatus)
Flax Lily (Dianella caerulea)
King’s Mantle (Thunbergia erecta)
Little Boy Blue (Otacanthus caeruleus)
Native Bluebell (Wahlenbergia species)
Native Sarsaparilla (Hardenbergia violacea)
Native Violet (Viola banksii)
Slug Herb (Murdannia graminea)
Snail Flower (Vigna caracalla)
Tropical Lilac (Lonchocarpus violaceus)

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