Balaustion grandibracteatum is a species of flowering plant in the family Myrtaceae and is endemic to inland Western Australia. It is a shrub with mostly narrowly oblong to elliptic leaves and white flowers with 14 to 27 stamens.
Balaustion grandibracteatum is a shrub that typically grows to high and wide. Its leaves are mostly narrowly oblong to elliptic, long and wide on a petiole long. Its flowers are borne singly or in pairs on a peduncle long, each flower in diameter and sessile. The floral tube is long and wide and the sepals are egg-shaped, long and wide. The petals are white, long with 14 to 27 stamens. Flowering time depends on subspecies, and the fruit is a capsule long and wide.
This species was first formally described in 1904 by Ernst Georg Pritzel who gave it the name Baeckea grandibracteata Engler's journal Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie in an article by Pritzel and Ludwig Diels entitled Fragmenta Phytographiae Australiae occidentalis. In 2022, Barbara Lynette Rye transferred the species to Balaustion as B. grandibracteatum in the journal Nuytsia. The specific epithet (grandibracteatum) is from the Latin grandis meaning 'great, large or tall' and bracteatus meaning , referring to the large bracteoles enclosed the mature flower buds.
In the same edition of Nuytsia, Rye described three subspecies of B. grandibracteatum, and the names are accepted by Plants of the World Online:
Balaustion grandibracteatum has been recorded between the Southern Cross area to near Hyden and Frank Hann National Park in the Avon Wheatbelt, Coolgardie and Mallee bioregions of inland Western Australia. Subspecies grandibracteatum has been recorded from west of Southern Cross to Yellowdine and the Parker Range area where it often grows in yellow sand in the Avon Wheatbelt and Coolgardie bioregions. Subspecies junctura is found from the Mount Holland to the Forrestania area in the Coolgardie and Mallee bioregions and subsp. meridionalis occurs from the Mount Gibbs to beyond the eastern end of Frank Hann National, where both subspecies grow in sandy soils, sometimes with lateritic gravel or granite cobbles in shrubland.
Balaustion grandibracteatum is listed as "not threatened" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, but subsp. grandibracteatum is listed as "Priority Three" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, meaning that it is poorly known and known from only a few locations but is not under imminent threat, but subsp. junctura and subsp. meridionale as "Priority Two", meaning that they are poorly known and from one or a few locations.