Hypocalymma elongatum is a species of flowering plant in the myrtle family Myrtaceae, and is endemic to the south west of Western Australia.

It is a large, bushy shrub with linear leaves more or less triangular in cross section, and pink flowers arranged in pairs in leaf axils with 30 to 50 stamens.

The flowers are arranged in pairs in leaf axils, more or less sessile or occasionally on peduncles up to 2 mm (0.079 in) long.

[2][6] In 2020 Barbara Lynette Rye raised it to species status as Hypocalymma elongatum in the journal Nuytsia.

[8] Hypocalymma elongatum grows in sandy soils in the area around the Stirling Range, from the Hamilla Hill Nature Reserve to Wellstead in the Avon Wheatbelt, Esperance Plains and Jarrah Forest bioregions of south-western Western Australia.