The Buxaceae are a small

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of six genera and about 123 known species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s. They are

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s and small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s, with a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

. A seventh genus, sometimes accepted in the past (''Notobuxus''), has been shown by genetic studies to be included within ''

Buxus ''Buxus'' is a genus of about seventy species in the family Buxaceae. Common names include box and boxwood. The boxes are native to western and southern Europe, southwest, southern and eastern Asia, Africa, Madagascar, northernmost So ...

'' (Balthazar ''et al.'', 2000). The family is recognised by most taxonomists, and it is commonly known as the

box A box (plural: boxes) is a container with rigid sides used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides (typically rectangular prisms). Boxes can be very small (like a matchbox) or v ...

family. However, its placement and circumscription has varied; some taxonomists treated '' Styloceras'' in its own family Stylocerataceae, '' Didymeles'' in its own family Didymelaceae, '' Haptanthus'' in Haptanthaceae (now all included in Buxaceae)), and formerly '' Simmondsia'' was included, which is not related and now usually placed in its own family Simmondsiaceae. The

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly Molecular phylogenetics, molecular-based, list of systems of plant taxonomy, system of plant taxonomy that ...

of 2003 recognises the family, but in a new circumscription in that it includes the genus '' Didymeles'' (two species of evergreen trees from Madagascar). However, APG II does allow the option of segregating this genus as family Didymelaceae, as an optional segregate. This represents a slight change from the

APG system The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved ...

of 1998, which firmly recognised both families as separate. In both APG and APG II, the family Buxaceae is unplaced as to order and left among the basal lineages of the

eudicots The eudicots or eudicotyledons are flowering plants that have two seed leaves (cotyledons) upon germination. The term derives from ''dicotyledon'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors h ...

. Th
AP website
suggests instating the order Buxales for this family and the family Didymelaceae. In the

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...

of 2016, ''Haptanthus'' and ''Didymeles'' are included in Buxaceae, which is the only family in Buxales.

References

*Balthazar, M. von, Peter K. Endress, P. K., and Qiu, Y.-L. 2000. Phylogenetic relationships in Buxaceae based on nuclear internal transcribed spacers and plastid ''ndhF'' sequences. ''Int. J. Plant Sci''. 161(5): 785–792 (availabl
online
.

in L. Watson and M.J. Dallwitz (1992 onwards)
''The families of flowering plants''
Eudicot families {{eudicot-stub