Do both Tithonia and Pachysandra belong to the taxonomic category of genus?
Pachysandra Pachysandra is a genus of five species of evergreen perennials or subshrubs, belonging to the boxwood family Buxaceae. The species are native to eastern Asia and southeast North America, some reaching a height of 20 - , with only weakly woody stems. The leaves are alternate, leathery, with an entirely too coarsely toothed margin, and are typically 5 - long. The small uni-sexual blooms are greenish-white and produced in late spring or early summer.
History of Pachypodium The history of the genus Pachypodium as a scientific classification began in 1830, when the genus was first used in a taxonomical system by John D. Lindley, who placed a single species, "P. tuberosum", in it. Lindley believed that this species was identical with one identified in 1781 as "Echites succulenta", which would make "Pachypodium" a taxonomical synonym of "Echites".