FrangulaceaeDC. PhylicaceaeJ.Agardh ZiziphaceaeAdans. ex Post & Kuntze[1]
TheRhamnaceae are a largefamily offlowering plants, mostly trees,shrubs, and some vines, commonly called thebuckthorn family.[2] Rhamnaceae is included in the orderRosales.[3]
The family contains about 55 genera and 950 species.[4] 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.[5]
Leaves of family Rhamnaceae members aresimple, i.e., the leaf blades are not divided into smaller leaflets.[2] Leaves can be either alternate oropposite. Stipules are present and modified into spines in many genera. In some (e.g.Paliurus spina-christi andColletia paradoxa) spectacularly so.Colletia stands out by having twoaxillary buds instead of one, one developing into a thorn, the other one into a shoot.
Theflowers 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 4stamens are opposite the petals.[2] Theovary is mostly superior, with 2 or 3ovules (or one by abortion).
Thefruits are mostly berries, fleshydrupes, or nuts. Some are adapted to wind carriage, but most are dispersed by mammals and birds. Chinese jujube is the fruit of thejujube tree (Ziziphus jujuba) and is a major fruit in China.
Economic uses of the Rhamnaceae are chiefly as ornamental plants and as the source of many brilliant green and yellowdyes. Thewood ofRhamnus was also the most favoured species to makecharcoal for use ingunpowder before the development of modern propellants.
The fossil record of the family extends back to the Late Cretaceous, with records from Colombia[11] and Mexico.[12] Remains from the mid-CretaceousBurmese amber of Myanmar have been suggested to belong to this family by some authors[13][14], but this has been doubted by others.[15] The earliest fossils of modern genera of the family date to the Eocene.[16]
^Hauenschild F, Matuszak S, Muellner-Riehl AN, Favre A (2016). "Phylogenetic relationships within the cosmopolitan buckthorn family (Rhamnaceae) support the resurrection ofSarcomphalus and the description ofPseudoziziphus gen. nov".Taxon.65 (1):47–64.Bibcode:2016Taxon..65...47H.doi:10.12705/651.4.JSTORtaxon.65.1.47.
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