Rhamnaceae

The Rhamnaceae are a large <a href="/facts/Family_(biology)/qTrn6E8E">family</a> of <a href="/facts/Flowering_plant/E5eGYIvY">flowering plants</a>, mostly trees, <a href="/facts/Shrub/X1gKVxL5">shrubs</a>, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order <a href="/facts/Rosales/H73YkSeg">Rosales</a>.
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 <a href="/facts/Simple_leaf/1m6wCNTg">simple</a>, i.e., the leaf blades are not divided into smaller leaflets. Leaves can be either alternate or <a href="/facts/Opposite_leaves/8xGtgllo">opposite</a>. Stipules are present and modified into spines in many genera. In some (e.g. <a href="/facts/Paliurus_spina-christi/A1Ego7Ym">Paliurus spina-christi</a> and Colletia paradoxa) spectacularly so. Colletia stands out by having two <a href="/facts/Axil/1m6wCNTg">axillary</a> buds instead of one, one developing into a thorn, the other one into a shoot.

The <a href="/facts/Flower/7gI5Kefw">flowers</a> 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 <a href="/facts/Stamen/MzNPVK3D">stamens</a> are opposite the petals. The <a href="/facts/Ovary_(plants)/Qug4yDY4">ovary</a> is mostly superior, with 2 or 3 <a href="/facts/Ovule/DFvS1VvA">ovules</a> (or one by abortion).
The <a href="/facts/Fruit/PBpuzk60">fruits</a> are mostly berries, fleshy <a href="/facts/Drupe/WrnGMPSa">drupes</a>, or nuts. Some are adapted to wind carriage, but most are dispersed by mammals and birds. Chinese jujube is the fruit of the <a href="/facts/Jujube/VXXRm594">jujube</a> tree (Ziziphus jujuba) and is a major fruit in China.
The American genus <a href="/facts/Ceanothus/jdF1oqEY">Ceanothus</a>, which has several showy <a href="/facts/Ornamental_plant/ImyCDwMW">ornamental</a> species, has <a href="/facts/Nitrogen_fixation/TeLoBpWS">nitrogen-fixing</a> <a href="/facts/Root_nodule/qUFHMpsq">root nodules</a>.
Economic uses of the Rhamnaceae are chiefly as ornamental plants and as the source of many brilliant green and yellow <a href="/facts/Dye/a1NSlcsG">dyes</a>. The <a href="/facts/Wood/z13NpHPl">wood</a> of <a href="/facts/Rhamnus_(plant)/tmKe17jp">Rhamnus</a> was also the most favoured species to make <a href="/facts/Charcoal/tpYGBHTn">charcoal</a> for use in <a href="/facts/Gunpowder/AEcB6HCR">gunpowder</a> before the development of modern propellants.

Rhamnaceae open-in-new

Rhamnaceae