Question: To which taxonomic category do both Cibotium and Dipteronia belong?
Context: Cibotium (from the Greek "kibootion", meaning chest or box) is a genus of 11 species of tropical tree fern—subject to much confusion and revision—distributed fairly narrowly in Hawaiʻ i (four species, plus a hybrid, collectively known as hāpuʻ u), Southeast Asia (five species), and the cloud forests of Central America and Mexico (two species).  Some of the species currently listed in the literature seem to be synonyms or local-variant subspecies. " Cibotium glaucum", from Hawaiʻ i, is the most frequently encountered "Cibotium" species in the horticultural trade, together with its sibling species "Cibotium chamissoi" and the potentially huge "Cibotium menziesii".  The remaining Hawaiian "Cibotium", "C. nealiae", is a 1 m dwarf variety, restricted to the island of Kauaʻ i that is never seen in the horticultural trade.  Precise identification of "Cibotium" species is difficult, although all have shiny and rather waxy fronds when viewed from above, with varying degrees of powdery-pale blush when seen from underneath.  The natural habitat of "Cibotium" is among the dripping trees and stream gullies of the rainforests on Hawaiʻ i's windward volcanic slopes. Aptera is an obsolete taxonomic category, which included the Apterygota along with various other wingless arthropods. Cladorhiza segonzaci is a species of sponge in the taxonomic category of Demospongiae.  The body of the sponge consists of a spicule and fibers and is water absorbent. Heterostropha was a previously used taxonomic category, an order of sea snails, within the superorder Heterobranchia.  In the most current gastropod taxonomy, that of Bouchet & Rocroi, this taxon is no longer in use. Gammaridae is a family of amphipods.  In North America they are included among the folk taxonomic category of "scuds", and otherwise gammarids is usually used as a common name. Dipteronia is a genus of two living and one extinct species, regarded in the soapberry family Sapindaceae "sensu lato" after Angiosperm Phylogeny Group (APG I 1998, APG II 2003) and more recently (Harrington "et al." 2005) )or traditionally by several authors in Aceraceae, related to the maples. Helleborine is the common name for a number of species of orchid.  It does not correspond to any currently used taxonomic category.  Some of the plants called helleborines are classified in the genus "Epipactis", some in genus "Cephalanthera".  A genus "Helleborine" was formerly recognised but has now been absorbed into the Grass pink genus "Calapogon". Sigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs.  This is an informal group which includes the majority of land snails and slugs. Cladorhiza inversa is a species of sponge in the taxonomic category of Demospongiae.  The body of the sponge consists of a spicule and fibers and is water absorbent. Eogastropoda was a previously used taxonomic category of snails or gastropods, a subclass which was erected by Ponder and Lindberg in 1997.  It was one of two great divisions (subclasses) of the class Gastropoda, the snails.  The other subclass of gastropods was the Orthogastropoda.
Answer: genus