Dianella congesta, commonly known as beach flax lily, is a species of flowering plant in the family Asphodelaceae. It is a shrub up to high, with blue flowers.
The species is native to Australia, and was described in 1810.
Taxonomy The species was described by Robert Brown in 1810. Frederick Manson Bailey placed it as a variety of Dianella caerulea. Jakob Schlittler placed it as a form of Dianella nemorosa (a synonym of Dianella ensifolia).
Distribution Dianella congesta is native to the seasonally dry tropical biome of south-east Queensland and eastern New South Wales, Australia. It grows mainly on coastal sand dunes, and is an effective sand-binder.
Description Dianella congesta is a subshrub or shrub. It grows up to high, and forms mats that can be wide at the base. The stems are long. The roots are fibrous.
The leaves are long, wide, and curved downwards.
The inflorescences are narrowly cylindrical, and have two to eight flowers. The flower stems are less than long. The perianth segments are blue, and elliptic to ovate-elliptic. The sepals are long. The petals are long. The plant flowers in spring and summer.
The berries are long. The seeds are long. The seed case is smooth, black, and shiny.
Dianella congesta is closely related to Dianella caerulea.
Uses Dianella congesta has sometimes been used in horticulture and landscaping.
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