Question: Pseudotsuga, found in North America and Eastern Asia which has also been classified as 'Abies' and 'Tsuga' and Huernia which is found in Eastern and Southern Africa and closely related to 'Stapelia' and 'Hoodia' are both types of what?
Context: Firs (Abies) are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae.  They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range.  Firs are most closely related to the genus "Cedrus" (cedar).  Douglas firs are not true firs, being of the genus "Pseudotsuga". The genera of plants within the tribe Stapeliae are all to varying degrees stem succulents.  Many of the species resemble cacti, though are not closely related, as an example of convergent evolution.  The stems are often angular, mostly four-angled in cross-section, but in some species there are six or more, with some species of "Hoodia" having more than thirty angles.  In size they vary from less than 2.5 cm/1" in length to over 2 m/6" tall.  The leaves are in most species reduced to rudiments, sometimes hardened and thorn-like, arranged on bumps or tubercles on the angles.  Some species, however, still have recognisable leaves, most notably the Indian species "Frerea indica", and some members of "Tridentea".  Stapeliads are most abundant in warm, dry climates.  In Africa, there are two separate regions where Stapeliads have most diversified: northeast Africa, and Southern Africa.  Several species are endemic to the small island of Socotra off the Horn of Africa.  The Arabian Peninsula, and most specifically the country of Yemen, contain another concentration of species.  Several more are found in the drier parts of Pakistan, Afghanistan, India, Nepal, and Myanmar.  A single species, "Caralluma europea" is found in Europe, in the very southern part of the Iberian peninsula.  Stapeliads are often regarded as a climax group within the family because of their often structurally complex flowers. Certain aspects of these reproductive parts mirror the pollination systems in the Orchid family and represent a case of parallel evolution though both groups are quite unrelated and have developed similar, though not identical means to achieve the ultimate goal of pollination and therefore reproduction.  Most stapeliads use flies as pollinators, that are attracted to odours resembling dung or rotting meat, emanating from the flowers.  Many of the flowers also bear some physical resemblance to rotting animal carcasses, leading to their popular name of Carrion Flowers.  However, not all stapeliads smell bad, or attract flies.  Some species use beetles, bees, wasps, butterflies or moths as pollinators.  Stapeliad flowers range in size from mere millimetres in species of "Echidnopsis" and "Pseudolithos" to those of "Stapelia gigantea" that can reach 40 cm/16" in diameter, and are some the largest of flowers to be found on any species of succulent. Amanita smithiana, also known as Smith's amanita, is a species of agaric found on soil in coniferous ("Abies", "Tsuga", "Pseudotsuga") and broadleaved ("Alnus", "Quercus") woodland in the Pacific Northwest of North America.  It fruits in August and September. Leptoceratopsidae is an extinct family of neoceratopsian dinosaurs from Asia and North America.  They resembled, and were closely related to, other neoceratopsians, such as the families Protoceratopsidae and Ceratopsidae, but they are more primitive and generally smaller.  Definitive leptoceratopsids have so far been found exclusively in the Late Cretaceous period (late Santonian - late Maastrichtian stages) of Asia and Western North America; however, material referred to leptoceratopsids from the early Campanian of North Carolina and possibly Sweden extends their geographic range into Eastern North America and potentially Europe.  A possible leptoceratopsid ulna, named "Serendipaceratops", has been found in Victoria, Australia.  However, a 2010 study showed that it could not be confidently referred to any ornithischian family, and is considered a "nomen dubium". Hemlock woolly adelgid ("Adelges tsugae"), or HWA, is member of the Sternorrhyncha suborder of the Order Hemiptera and native to East Asia.  It feeds by sucking sap from hemlock and spruce trees ("Tsuga" spp.; "Picea" spp.) .  In eastern North America, it is a destructive pest that gravely threatens the eastern hemlock ("Tsuga canadensis") and the Carolina hemlock ("Tsuga caroliniana").  Though the range of eastern hemlock extends north of the current range of the adelgid, it could spread to infect these northern areas as well.  Accidentally introduced to North America from Japan, HWA was first found in the eastern United States near Richmond, Virginia, in the early 1950s.  The pest has now been established in eighteen eastern states from Georgia to Massachusetts, causing widespread mortality of hemlock trees.  As of 2015, 90% of the geographic range of eastern hemlock in North America has been impacted by HWA. Stem succulents are fleshy succulent columnar shaped plants which conduct photosynthesis mainly through stems not leaves.  They are related by form, but not by evolution.  They evolved to have similar forms and physiological characteristics by convergent evolution.  Examples are tall thin "Euphorbias" from deserts and arid regions southern African and Madagascar, similarly shaped cacti from North America and South America, which occupy a similar evolutionary niche, and members of two genera of the family Asclepiadaceae ("Hoodia" and "Stapelia").  Shared features are a succulent stem that stores water and conducts photosynthesis, protective spines or thorns, no leaves (or highly reduced leaves), and use of CAM photosynthetisis (an opening of stomata and fixing CO2 almost exclusively at night). Pseudotsuga is a genus of evergreen coniferous trees in the family Pinaceae.  Common names include Douglas fir, Douglas-fir, Douglas tree, and Oregon pine. " Pseudotsuga menziesii" is widespread in western North America and is an important source of timber.  The number of species has long been debated, but two in western North America and two to four in eastern Asia are commonly acknowledged.  Nineteenth-century botanists had problems in classifying Douglas-firs, due to the species' similarity to various other conifers better known at the time; they have at times been classified in "Pinus", "Picea", "Abies", "Tsuga", and even "Sequoia".  Because of their distinctive cones, Douglas-firs were finally placed in the new genus "Pseudotsuga" (meaning "false hemlock") by the French botanist Carrière in 1867.  The genus name has also been hyphenated as "Pseudo-tsuga". Celtis, commonly known as hackberries or nettle trees, is a genus of about 60–70 species of deciduous trees widespread in warm temperate regions of the Northern Hemisphere, in southern Europe, southern and eastern Asia, and southern and central North America, south to central Africa, and northern and central South America.  The genus is present in the fossil record at least since the Miocene of Europe, and Paleocene of North America and eastern Asia. Pseudotsuga menziesii" var.  "glauca, or Rocky Mountain Douglas-fir, is an evergreen conifer native to the interior mountainous regions of western North America, from central British Columbia and southwest Alberta in Canada southward through the United States to the far north of Mexico.  The range is continuous in the northern Rocky Mountains south to eastern Washington, eastern Oregon, Idaho, western and south-central Montana and western Wyoming, but becomes discontinuous further south, confined to "sky islands" on the higher mountains in Utah, Colorado, Arizona and New Mexico, with only very isolated small populations in eastern Nevada, westernmost Texas, and northern Mexico.  It occurs from 600 m altitude in the north of the range, up to 3,000 m, rarely 3,200 m, in the south.  Further west towards the Pacific coast, it is replaced by the related coast Douglas-fir ("Pseudotsuga menziesii" var.  "menziesii"), and to the south, it is replaced by Mexican Douglas-fir in high mountains as far south as Oaxaca.  Some botanists have grouped Mexican Douglas-fir with "P. menziesii" var.  "glauca", but genetic and morphological evidence suggest that Mexican populations should be considered a different variety. The genus Huernia (family Apocynaceae, subfamily Asclepiadoideae) consists of stem succulents from Eastern and Southern Africa, first described as a genus in 1810.  The flowers are five-lobed, usually somewhat more funnel- or bell-shaped than in the closely related genus "Stapelia", and often striped vividly in contrasting colours or tones, some glossy, others matt and wrinkled depending on the species concerned.  To pollinate, the flowers attract flies by emitting a scent similar to that of carrion.  The genus is considered close to the genera "Stapelia" and "Hoodia".  The name is in honour of Justin Heurnius (1587–1652) a Dutch missionary who is reputed to have been the first collector of South African Cape plants.  His name was actually mis-spelt by the collector.
Answer: genus