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?

<P0-S0> Stem succulents are fleshy succulent columnar shaped plants which conduct photosynthesis mainly through stems not leaves. <P0-S1>  They are related by form, but not by evolution. <P0-S2>  They evolved to have similar forms and physiological characteristics by convergent evolution. <P0-S3>  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"). <P0-S4>  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). <SEP> <P1-S0> Leptoceratopsidae is an extinct family of neoceratopsian dinosaurs from Asia and North America. <P1-S1>  They resembled, and were closely related to, other neoceratopsians, such as the families Protoceratopsidae and Ceratopsidae, but they are more primitive and generally smaller. <P1-S2>  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. <P1-S3>  A possible leptoceratopsid ulna, named "Serendipaceratops", has been found in Victoria, Australia. <P1-S4>  However, a 2010 study showed that it could not be confidently referred to any ornithischian family, and is considered a "nomen dubium". <SEP> <P2-S0> Pseudotsuga is a genus of evergreen coniferous trees in the family Pinaceae. <P2-S1>  Common names include Douglas fir, Douglas-fir, Douglas tree, and Oregon pine. " <P2-S2> Pseudotsuga menziesii" is widespread in western North America and is an important source of timber. <P2-S3>  The number of species has long been debated, but two in western North America and two to four in eastern Asia are commonly acknowledged. <P2-S4>  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". <P2-S5>  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. <P2-S6>  The genus name has also been hyphenated as "Pseudo-tsuga". <SEP> <P3-S0> The genus Huernia (family Apocynaceae, subfamily Asclepiadoideae) consists of stem succulents from Eastern and Southern Africa, first described as a genus in 1810. <P3-S1>  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. <P3-S2>  To pollinate, the flowers attract flies by emitting a scent similar to that of carrion. <P3-S3>  The genus is considered close to the genera "Stapelia" and "Hoodia". <P3-S4>  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. <P3-S5>  His name was actually mis-spelt by the collector.