About Oxypetalum coeruleum (D.Don ex Sweet) Decne.
Oxypetalum coeruleum (D.Don ex Sweet) Decne., a flowering plant species also known by the synonym Tweedia caerulea, is native to South America, ranging from southern Brazil to Uruguay. This straggling evergreen perennial grows to 100 cm (39 in) long, and produces heart-shaped, gray-green, downy leaves. It is cultivated for its clear pale blue, long-lasting star-shaped flowers that work well for cutting. Summer blooms age to purple, and are followed by 30 cm (12 in) long, boat-shaped seed pods. The seeds are cypsela, with downy parachute-like tufts. Two cultivars are available: 'Alba' has white flowers, while 'Rosea' has pink flowers. Oxypetalum coeruleum needs full sun and well-drained, dry soil, and is propagated by seed. It tolerates a minimum temperature between 3–5 °C (37–41 °F); it can be grown outdoors in frost-free, sheltered locations, or alternatively grown as an annual. This plant has received the Royal Horticultural Society's Award of Garden Merit.
