For nearly two hundred years they were considered a separate genus, having been published at that rank in 1810 by Robert Brown.
Later that year, he republished his descriptions of Dryandra in his Prodromus Florae Novae Hollandiae et Insulae Van Diemen.
He added a further 11 species to Dryandra, but transferred D. falcata into a new, monospecific genus as Hemiclidia Baxteri, on the grounds that its follicles always contained only a single seed.
The remaining 23 Dryandra species were divided into three sections based on the number of seed separators in each follicle.
Aphragmia was defined as containing four species that Brown thought lacked a seed separator altogether.
In the interim a number of new species were published, notably in John Lindley's 1839 A Sketch of the Vegetation of the Swan River Colony, and by Meissner in J. G. C. Lehmann's 1845 Plantae Preissianae.
Armatae because "as far as I can understand the characters given, the difference in the fruit upon which the genus Hemiclidia was founded is merely the result of the abortion of one ovule, which occurs occasionally or perhaps constantly in one or two other species of Dryandra.
Thus the rich infrageneric classification of Dryandra, including all of Brown's taxa, has been set aside, at least temporarily.