Question: What type of category does Bletilla and Vernonia have in common?

Context articles: Bletilla
Vernonia
Vernonia proctorii
Vernonia amygdalina
Fitkid
Butin (molecule)
Category utility
Tarlmounia
Internal category
Yoneda lemma

Bletilla, common name urn orchid, is a temperate, terrestrial genus of orchids containing five currently recognized species distributed through China, Japan, Taiwan, south to Vietnam, Thailand and Myanmar.
 The name is actually a diminutive of "Bletia" because of the resemblance between the two genera even though Bletia is a New World genus.
 The genera Jimensia and Polytoma are generally included into "Bletilla".
 This genus is abbreviated Ble in trade journals.
Vernonia is a genus of about 1000 species of forbs and shrubs in the family Asteraceae.
 Some species are known as ironweed.
 Some species are edible and of economic value.
 They are known for having intense purple flowers.
 The genus is named for the English botanist William Vernon.
 There are numerous distinct subgenera and subsections in this genus.
 This has led some botanists to divide this large genus into several distinct genera.
 For instance, the "Flora of North America" only recognizes about 20 species in "Vernonia" sensu stricto, 17 of which are in North America north of Mexico, with the others being found in South America.
Vernonia proctorii is a rare species of flowering plant in the aster family known by the common name Proctor's ironweed.
 It is endemic to Puerto Rico, where there are two populations.
 It is threatened by the destruction of its habitat.
 It is a federally listed endangered species of the United States.
Vernonia amygdalina, a member of the Asteraceae family, is a small shrub that grows in tropical Africa.
 "V. amygdalina" typically grows to a height of 2-5 m .
 The leaves are elliptical and up to 20 cm long.
 Its bark is rough.
 "V. amygdalina" is commonly called bitter leaf in English because of its bitter taste.
 The cooked leaves are a staple vegetable in soups and stews of various cultures throughout equatorial Africa.
 African common names include grawa (Amharic), ewuro (Yoruba), etidot (Ibibio), onugbu (Igbo), ityuna (Tiv), oriwo (Edo), chusar-doki (Hausa), mululuza (Luganda), labwori (Acholi), olusia (Luo), and ndoleh (Cameroon).
Fitkid (also "FitKid", "Fit Kid" or "Fit-Kid") is a type of children's sport combining gymnastics, dance and acrobatics.
 It originated in Europe in the 1990s, and is meant to engage children 8–18 years of age in fun individual and group exercise, free of the extremes of more strenuous aerobics or traditional gymnastics.
 International competitions are organized regularly by the "International FitKid Division", in addition to national competitions.
 A routine stands of four types of elements: strength, flexibility, acrobatics, and jumps.
 All elements are graded by difficulty from A to H.
 A elements being worth 0.1 points, B 0.2, C 0.3, and so on until H which is worth 0.8.
 Routines get evaluated in three categories: technique, artistry, and content (execution of elements).
 Competition is divided by age groups (I. to IX.
 (or Senior in A category)), and categories ( which are based on knowledge).
 There three categories (from hardest to easiest) A, B, and C, also called Dance.
 In each categories there are group and individual routines.
 In C Category (here group routines are also called Dance Show) team member can go from 4 to 8.
 In A and B category there are duos, small groups (3-4), and big groups (5-6).
 In C category, individually 4 elements have to be performed ( one from each type), A or B difficulty, and in groups, two are optional.
 In B category individually 8 elements need to be performed ( two from each type) A-D difficulty ( but max.
 two elements can be D), and in groups 4 (same as C category individual).
 In A category team and individual, 8 elements need to be performed (same as B category) and an acrobatic connection is optional.
 Skills in A category can be any difficulty.
Butin is a flavanone, a type of flavonoid.
 It can be found in the seeds of "Vernonia anthelmintica" (Asteraceae) and in the wood of "Dalbergia odorifera" (Fabaceae).
Category utility is a measure of "category goodness" defined in and .
 It attempts to maximize both the probability that two objects in the same category have attribute values in common, and the probability that objects from different categories have different attribute values.
 It was intended to supersede more limited measures of category goodness such as "cue validity" (; ) and "collocation index" .
 It provides a normative information-theoretic measure of the "predictive advantage" gained by the observer who possesses knowledge of the given category structure (i.e., the class labels of instances) over the observer who does "not" possess knowledge of the category structure.
 In this sense the motivation for the "category utility" measure is similar to the information gain metric used in decision tree learning.
 In certain presentations, it is also formally equivalent to the mutual information, as discussed below.
 A review of "category utility" in its probabilistic incarnation, with applications to machine learning, is provided in .
Tarlmounia is a plant genus in the family Asteraceae.
 The sole species is Tarlmounia elliptica (syn.
 "Vernonia elliptica" and "V. elaeagnifolia"), native to India, Burma and Thailand and naturalised in southern Taiwan and Queensland, Australia.
 Common names include curtain creeper, vernonia creeper and parda bel.
In mathematics, more specifically in category theory - internal categories are a generalisation of the notion of small category, and are defined with respect to a fixed ambient category.
 If the ambient category is taken to be the category of sets then one recovers the theory of small categories.
 In general, internal categories consist of a pair of objects in the ambient category - thought of as the 'object of objects' and 'object of morphisms', together with a collection of morphisms in the ambient category satisfying certain identities.
 Group objects, are common examples of internal categories.
In mathematics, specifically in category theory, the Yoneda lemma is an abstract result on functors of the type "morphisms into a fixed object".
 It is a vast generalisation of Cayley's theorem from group theory (viewing a group as a particular kind of category with just one object).
 It allows the embedding of any category into a category of functors (contravariant set-valued functors) defined on that category.
 It also clarifies how the embedded category, of representable functors and their natural transformations, relates to the other objects in the larger functor category.
 It is an important tool that underlies several modern developments in algebraic geometry and representation theory.
 It is named after Nobuo Yoneda.