As far as we know, the eastern pincushion was first collected between 1799 and 1803 from the north face of the Outeniqua Mountains by Scottish plant collector James Niven. Richard Anthony Salisbury described the species based on Niven's material in a book published by Joseph Knight in 1809 titled On the cultivation of the plants belonging to the natural order of Proteeae, and called it Leucadendrum royenaefolium. In 1856 Carl Meisner described Leucospermum puberum var. dubium. Salisbury's names were ignored by botanists in favour of those that Brown had created, and this was formalised in 1900 when Leucospermum was given priority over Leucadendrum. Compton reassigned the eastern pincushion to the genus Leucospermum, and created the new combination Leucospermum royenaefolium in 1912. In 1970, John Patrick Rourke considered all of these names synonymous. During the 1970s, the International Botanical Congress decided to replace all instances of compounding by the genitive ae by i, thus changing the spelling of the name of this species to Leucospermum royenifolium.