Seeds from Iris Patersonia occidentalis alba. The three petaled flowers are pale blue, mauve and purple or rarely white. The large blooms may be up to seven centimeters in diameter. Flowering occurs in spring and summer. Each flower lasts for less than a day but mature plants will produce a procession of flowers for many months. Patersonia occidentalis is a widespread species and is found in Victoria, Tasmania, South Australia and Western Australia. The Western Australian population is said to be the most robust and carry more flowers. Patersonia occidentalis would be an ideal addition to native cottage gardens and rockeries. An eye catching display would be created by mass planting the Long Purple Flag. There are about 20 Patersonia species. Of these 18 are endemic in Australia. As yet they are not widely cultivated but have great horticultural potential. Germination is difficult. Treatment with smoked water 6 to 36 hours or a top dressing of wood ash.