The Rhamnaceae are a large

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 ...

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, mostly trees,

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 some vines, commonly called the buckthorn family. Rhamnaceae is included in the order

Rosales Rosales (, ) are an order of flowering plants. Peter F. Stevens (2001 onwards). "Rosales". At: Trees At: Angiosperm Phylogeny Website. At: Missouri Botanical Garden Website. (see ''External links'' below) Well-known members of Rosales include: ...

. The family contains about 55 genera and 950 species. The Rhamnaceae have a worldwide distribution, but are more common in the subtropical and tropical regions. The earliest fossil evidence of Rhamnaceae is from the Late Cretaceous. Fossil flowers have been collected from the Upper Cretaceous of Mexico and the Paleocene of Argentina. Leaves of family Rhamnaceae members are

simple Simple or SIMPLE may refer to: *Simplicity, the state or quality of being simple Arts and entertainment * ''Simple'' (album), by Andy Yorke, 2008, and its title track * "Simple" (Florida Georgia Line song), 2018 * "Simple", a song by John ...

, i.e., the leaf blades are not divided into smaller leaflets.Flowering Plants of the Santa Monica Mountains, Nancy Dale, 2nd Ed. 2000, p. 166 Leaves can be either alternate or

opposite In lexical semantics, opposites are words lying in an inherently incompatible binary relationship. For example, something that is ''even'' entails that it is not ''odd''. It is referred to as a 'binary' relationship because there are two members i ...

. Stipules are present and modified into spines in many genera. In some (e.g. ''

Paliurus spina-christi ''Paliurus spina-christi'', commonly known as Jerusalem thorn, garland thorn, Christ's thorn, or crown of thorns, is a species of '' Paliurus'' native to the Mediterranean region, Southwest Asia and Central Asia, from Morocco and Spain east to ...

'' and ''

Colletia paradoxa ''Colletia'' is a genus of flowering plants in the family Rhamnaceae, with five species of spiny shrubs. All species of this genus are native to southern South America. They are non-legume nitrogen fixers. Taxonomy Species ''Colletia'' comprises ...

'') spectacularly so. ''Colletia'' stands out by having two

axil A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

lary buds instead of one, one developing into a thorn, the other one into a shoot. Ceanothus cuneatus1

The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are radially symmetrical. There are 5 (sometimes 4) separate sepals and 5 (sometimes 4 or none) separate petals. The petals may be white, yellowish, greenish, pink or blue, and are small and inconspicuous in most genera, though in some (e.g. ''Ceanothus'') the dense clusters of flowers are conspicuous. The 5 or 4

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s are opposite the petals. The

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

is mostly superior, with 2 or 3

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the sporangium, megasporangium), ...

s (or one by abortion). The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

s are mostly berries, fleshy

drupe In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

s, or nuts. Some are adapted to wind carriage, but most are dispersed by mammals and birds. Chinese jujube is the fruit of the

jujube Jujube (UK ; US or ), sometimes jujuba, scientific name ''Ziziphus jujuba'', and also called red date, Chinese date, and Chinese jujube, is a species in the genus '' Ziziphus'' in the buckthorn family Rhamnaceae. It is often confused wit ...

tree (''Ziziphus jujuba'') and is a major fruit in China. The American genus ''

Ceanothus ''Ceanothus'' is a genus of about 50–60 species of nitrogen-fixing shrubs and small trees in the buckthorn family (Rhamnaceae). Common names for members of this genus are buckbrush, California lilac, soap bush, or just ceanothus. ''"Ceanothus" ...

'', which has several showy

ornamental Ornamental may refer to: *Ornamental grass, a type of grass grown as a decoration *Ornamental iron, mild steel that has been formed into decorative shapes, similar to wrought iron work *Ornamental plant, a plant that is grown for its ornamental qua ...

species, has

nitrogen-fixing Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen ...

root nodule Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known ...

s. Economic uses of the Rhamnaceae are chiefly as ornamental plants and as the source of many brilliant green and yellow

dye Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...

s. The

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

of '' Rhamnus'' was also the most favoured species to make

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

for use in

gunpowder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...

before the development of modern propellants. Alphitonia ponderosa (6691195369).jpg, ''Alphitonia ponderosa'' Mountain flower white flower.jpg, ''Ceanothus'' Ceanothus papillosus var roweanus 2.jpg, ''Ceanothus papillosus'' var. ''roweanus'' at the Regional Parks Botanic Garden, Berkeley, California

Genera

Systematics

Modern

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

recommend the following clade-based classification of Rhamnaceae:

Fossil record

The fossil record of the family extends back to the Late Cretaceous, with records from Colombia and Mexico. Remains from the mid-Cretaceous

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. Th ...

of Myanmar have been suggested to belong to this family by some authors', but this has been doubted by others. The earliest fossils of modern genera of the family date to the Eocene.

References

External links

Rhamnaceae of Mongolia in FloraGREIF
{{Authority control Rosid families