The Actinidiaceae are a small

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s. The family has three genera and about 360

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

and is a member of the order

Ericales The Ericales are a large and diverse order of dicotyledons. Species in this order have considerable commercial importance including for tea, persimmon, blueberry, kiwifruit, Brazil nuts, argan, and azalea. The order includes trees, bushes, lia ...

Distribution

They are temperate and subtropical woody

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themsel ...

s, shrubs, and trees, native to Asia ('' Actinidia'' or

kiwifruit Kiwifruit (often shortened to kiwi in North American, British and continental European English) or Chinese gooseberry is the edible berry of several species of woody vines in the genus '' Actinidia''. The most common cultivar group of kiwi ...

, '' Clematoclethra'', and ''

Saurauia ''Saurauia'' is a genus of plants in the family Actinidiaceae. It comprises about over 300 species distributed in the tropics and subtropics of Asia and South and Central America. Genetic evidence and the cell biology of the group support monophy ...

'') and Central America and South America (''

'' only). ''Saurauia'', with its 300 species, is the largest genus in this family. Although now confined to Asia and tropical Central and South America, evidence indicates in the past the family had a wider distribution. The now extinct genus ''Parasaurauia'' is thought to have belonged to the Actinidiaceae and lived in North America during the early

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ...

Characteristics

The plants are usually small trees or shrubs, or sometimes vines (''Actinidia''). The alternate, simple, spiral leaves have serrated or entire margins. They lack

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s or are minutely stipulated. They are often beset with rather flattened bristles. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s grow solitary or are aggregated in terminal cymes, with free

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s and petals. Except for members of the genus ''Clematoclethra'' which have 10 stamens, the stamens are numerous and originally attached at the back. They invert just before the flower starts expanding, so their bases become

apical Apical means "pertaining to an apex". It may refer to: *Apical ancestor, refers to the last common ancestor of an entire group, such as a species (biology) or a clan (anthropology) *Apical (anatomy), an anatomical term of location for features loc ...

. The plants may be dioecious, monoecious, or

hermaphroditic In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have s ...

. The fruit is usually a berry, such as the edible kiwifruit, a cultivar from the genus ''Actinidia''.

Evidence supporting placement within the Ericales

Before genetic evidence appeared in the last 10 years, the placement of the Actinidiaceae within the Ericales was highly controversial. The

USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

Plants Database, a resource considered authoritative, still places the Actinidaceae within the

Theales Theales is a botanical name at the rank of order. Early classifications such as that of Dahlgren placed the Theales in the superorder Theiflorae (also called Theanae). The name was used by the Cronquist system for an order placed in subclass Dille ...

, an order which has been shown not to be monophyletic. Placement of the Actinidiaceae within the Ericales has been strongly supported recently by genetic evidence, and contrary to previous thought, it is not a basal member of the Ericales. Multiple studies using genetic evidence now firmly place the Actinidiaceae in the Ericoid clade, a monophyletic group consisting of the

Ericaceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

, the

Cyrillaceae The Cyrillaceae are a small family (biology), family of flowering plants in the order Ericales, native to warm temperate to tropical regions of the Americas. The family comprises two genera, ''Cliftonia'' and ''Cyrilla'', each containing a single ...

, the

Clethraceae The Clethraceae are a small family of flowering plants in the order Ericales, composed of two genera, ''Clethra'' and '' Purdiaea'', with approximately 75 species. They are native to warm temperate to tropical regions of Asia and the Americas, w ...

, the

Sarraceniaceae Sarraceniaceae are a family of pitcher plants, belonging to order Ericales (previously Nepenthales). The family comprises three extant genera: ''Sarracenia'' (North American pitcher plants), '' Darlingtonia'' (the cobra lily or California pitc ...

, and the Roridulaceae. Further genetic evidence points to the Actinidiaceae being sister to the Roridulaceae, with the Roridulaceae and Sarraceniaceae, forming another, smaller, monophyletic group.

Evidence supporting monophyly of the Actinidiaceae

What genera were to be placed in the Actinidiaceae before recent genetic and micromorphological studies emerged was highly controversial. Before recent evidence, the genus ''Sladenia'' was often placed within the Actinidiaceae. Also, ''Saurauia'' was sometimes considered its own family. Thus, before more detailed studies started, two to four genera could be placed within the Actinidiaceae. Micromorphological characters have confirmed that ''Sladenia'' does not belong in the Actinidiaceae. Furthermore, biological characteristics of the

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...

s, and molecular evidence have confirmed the three genera currently

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

in the Actinidiaceae, ''Clematoclethra'', ''Saurauia'', and ''Actinidia'', do indeed form a monophyletic group.

References

External links

Actinidiaceae
i
BoDD – Botanical Dermatology Database
{{Taxonbar, from=Q156666 Ericales families