Clinantheae is a tribe (in the family Amaryllidaceae, subfamily Amaryllidoideae), where it forms part of the Andean clade, one of two American clades.
 The tribe was described in 2000 by Alan Meerow "et al." as a result of a molecular phylogenetic study of the American Amaryllidoideae.
 This demonstrated that the Stenomesseae tribe, including the type genus "Stenomesson" was polyphyletic.
 Part of the tribe segregated with the Eucharideae and were submerged into it, while the other part formed a unique subclade.
 Since the type species of "Stenomesson" was not part of the second sublclade it was necessary to form a new name for the remaining species together with the other genera that remained.
 This was "Clinanthus", the oldest name for these species, and consequently the tribe Clinantheae.
Arctotis is a genus of annual and perennial plants in the family Asteraceae.
Stenomesseae was a tribe (in the family Amaryllidaceae, subfamily Amaryllidoideae), where it forms part of the Andean clade, one of two American clades.
 The tribe was originally described by Traub in his monograph on the Amaryllidaceae in 1963, as Stenomessae based on the type genus "Stenomesson".
 In 1995 it was recognised that Eustephieae was a distinct group separate from the other Stenomesseae.
 Subsequently, the Müller-Doblies' (1996) divided tribe Eustephieae into two subtribes, Stenomessinae and Eustephiinae.
Stenomesson is a genus of bulbous plants in the family Amaryllidaceae.
 All the species are native to western South America (Colombia, Ecuador, Peru and northern Chile).

Question: Stenomesson and Arctotis, are a type of what?
Answer: plants