Range: southwestern Australia, near Perth
Byblis gigantea is one of only 2 species of rainbow plant that lives as a perennial rather than annual plant, surviving in the winter-wet regions of southwestern Australia where it is found in sandy soils in peat swamps and wet depressions, often those that dry out almost entirely in summer. It grows to a height of approximately 30-45 cm, with a thick, occasionally branching stem supporting numerous filiform leaves up to 20 cm in length. Coloration is typically bright green, though may tinge reddish or purple under strong light. Flowers are borne singularly on stalks arising from between the leaves, often many produced at once; blooms may be nearly 4 cm across, with broad ovate to obovate petals that may have smooth or slightly serrated edges. Coloration ranges typically from light to deep violet, often darker in the center around the “banana cluster” of stamens, and rare white flowered forms are also known. Going dormant during the dry summer seasons, this species dies back to a woody rhizome before regrowing come winter rains.
Cultivation: grow in a large pot with a 3:2 sand/peat soil, kept moist to moderately wet (wild plants are sometimes inundated but cultivated may prefer it drier) and moderately humid during the growing season with temperatures of 50-75°F. During summer as the plant dies back allow the soil to dry to barely damp and keep temperatures warmer; if plants do not die back retain higher moisture in the soil. Sow seeds on soil surface after subjecting to smoke or GA3 treatment (500-1000 ppm for 4-6 days), or provide a long heat stratification period, and grow in full sun. Feed heavily; osmocote pellets in the soil at the base of each plant may be beneficial.
Lifespan and reproduction: perennial. Reproduces by seed with cross-pollination, or cuttings through root stock.
The flowers on this species are large, much like its other perennial relative.