Obsolete subgenus within the former genus "Dryandra"
Dryandra" subg. "Hemiclidia is an obsolete plant taxon that encompassed material that is now included in "Banksia". Published at genus rank as Hemiclidia by Robert Brown in 1830, it was set aside by George Bentham in 1870, but reinstated at subgenus rank by Alex George in 1996. In 2007, all "Dryandra" species were transferred into "Banksia" at series rank, and the infrageneric "Dryandra" taxa, including "D." subg. "Hemiclidia", were set aside.
According to Brown.
In 1810, Robert Brown published the genus "Dryandra" in his "On the Proteaceae of Jussieu". Thirteen species were published, including "Dryandra falcata" (now "Banksia falcata"), but no infrageneric arrangement was proffered. Twenty years later, Brown published a further eleven species and the first infrageneric arrangement in his "Supplementum primum prodromi florae Novae Hollandiae". By this time, Brown had observed the tendency in "D. falcata" for one of the two ovules in each follicle to abort, thereafter developing into a winglike appendage to the seed separator. On this basis, he transferred the species into a monotypic genus, which he named "Hemiclidia", from the Greek "hemi" ("half") and perhaps "kleidos" ("barrier", "means of closing").
"Hemiclidia" was retained in the 1856 arrangement of Carl Meissner, but discarded by George Bentham in his 1870 revision of the genus. Bentham correctly observed that the abortion of seeds occurs in other "Dryandra" species, and is a diagnostically unimportant character: ;templatestyles src="Template:Blockquote/styles.css" / ;"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"."
According to George.
In 1996, Alex George published a thorough revision of "Dryandra" in preparation of his monograph on that genus for the "Flora of Australia" series. He segregated "D. falcata" and the newly published "D. glauca" (now "Banksia glaucifolia") into a subgenus based on their unusual follicles, which are small, hairy and pliable. Needing a name for the subgenus, George noted that "Hemiclidia" was available, and had an appropriate type species in "D. falcata". He therefore demoted "Hemiclidia" to subgenus rank as "Dryandra" subg. "Hemiclidia" (R.Br.) A.S.George. Its placement and circumscription in George's taxonomic arrangement of "Dryandra" may be summarised as follows:
Genus "Dryandra" (now "Banksia" ser. "Dryandra")
Subgenus "Dryandra" (24 series, 91 species, 39 subspecies, 23 varieties)
Subgenus "Hemiclidia"
"D. falcata" (now "Banksia falcata")
"D. glauca" (now "Banksia glaucifolia")
Subgenus "Diplophragma" (1 species)
This arrangement remained current until 2007, when Austin Mast and Kevin Thiele transferred "Dryandra" into "Banksia". They were not yet ready, however, to tender an infrageneric arrangement encompassing "Dryandra", so as an interim measure they transferred "Dryandra" into "Banksia" at series rank. This minimised the nomenclatural disruption of the transfer, but also caused George's rich infrageneric arrangement to be set aside. Thus under the interim arrangements implemented by Mast and Thiele, "D." subg. "Hemiclidia" has been set aside.
References.
 ;templatestyles src="Reflist/styles.css" / ;