Thysanotus ramulosus is a species of flowering plant in the Asparagaceae family, and is endemic to the south-west of Western Australia. It is a leafless herb with a small rootstock, perennial stems, tuberous roots and flowers arranged singly, with linear to lance-shaped sepals, elliptic, fringed petals and six stamens of differing lengths.
Thysanotus ramulosus is a leafless herb with a small rootstock, perennial stems, tuberous roots, the tubers with a short stalk, about long and in diameter. The stems are perennial, about long, branched and or with scattered, flattened hairs. The upper branches are long with flowers arranged singly or in pairs on a pedicel long. The perianth segments are long, the sepals linear to narrowly lance-shaped, about wide and the petals elliptic, wide with a fringe long. There are six stamens, the anthers very slightly curved, the outer ones long, the inner three long. The style is about long. Flowering occurs in September, and the seeds are black, about long and in diameter with an aril.
Thysanotus ramulosus was first formally described in 1972 by Norman Henry Brittan in the Journal of the Royal Society of Western Australia from specimens he collected "just north of the crossing of Murchison River by North West Coastal Highway about north of Northampton" in 1968. The specific epithet (ramulosus) means 'bearing branchlets'.
This species of Thysanotus grows in sand over granite in red, stony loam in areas dominated by Acacia species, from the Murchison River to localities further east, in the Avon Wheatbelt, Geraldton Sandplains, Murchison and Yalgoo bioregions of south-western Western Australia.
Thysanotus ramulosus is listed as "not threatened" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions.