The Rhamnaceae are a large

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 t ...

s, mostly trees,

shrub A shrub (often also called a 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 tree ...

s, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales. 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 Johnn ...

, 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. Stipules are present. These leaves are 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 and southwest and central Asia, from Morocco and Spain east to ...

'' and ''

Colletia ''Colletia'' is a genus of flowering plants in the family Rhamnaceae, with five species of spiny shrubs. All species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well ...

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

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

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

Helinus integrifolius, blom, Skeerpoort, b

Ziziphus mucronata, blomme, Roodeplaat NR, c

Rhamnus saxatilis (Felsen-Kreuzdorn) IMG 7432

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 mechanis ...

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 (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the fila ...

s are opposite the petals. The

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

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 megasporangium), and the ...

s (or one by abortion). The

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

s are mostly berries, fleshy

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

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 tree (''Ziziphus zizyphus'') 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. ''"Ceanothu ...

'', which has several showy ornamental species, has nitrogen-fixing root nodules. Economic uses of the Rhamnaceae are chiefly as ornamental plants and as the source of many brilliant green and yellow

dye A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and ...

s. The

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

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, ...

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, carbon (in the form of charcoal) and potassium nitrate (saltpeter). T ...

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 The Regional Parks Botanic Garden is a 10-acre (4 hectare) botanical garden located in Tilden Regional Park in the Berkeley Hills, east of Berkeley, California, in the United States. It showcases California native plants, and is open to the publ ...

, 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:

References

External links

Rhamnaceae of Mongolia in FloraGREIF
{{Taxonbar, from=Q156083 Rosid families