Rumex

The docks and sorrels, genus Rumex L., are a genus of about 200 species of annual, biennial, and perennial herbs in the buckwheat family Polygonaceae.Members of this family are very common perennial herbs with a native almost worldwide distribution, with introduced species growing in the few places where the genus is not native. Some are nuisance weeds (and are sometimes called dockweed or dock weed), but some are grown for their edible leaves.Rumex species are used as food plants by the larvae of a number of Lepidoptera species, and are the only host plants of Lycaena rubidus. They are erect plants, usually with long taproots. The fleshy to leathery leaves form a basal rosette at the root. The basal leaves may be different from those near the inflorescence. They may or may not have stipules. Minor leaf veins occur. The leaf blade margins are entire or crenate. The usually inconspicuous flowers are carried above the leaves in clusters. The fertile flowers are mostly hermaphrodites, or they may be functionally male or female. The flowers and seeds grow on long clusters at the top of a stalk emerging from the basal rosette; in many species, the flowers are green, but in some (such as sheep's sorrel, Rumex acetosella) the flowers and their stems may be brick-red. Each seed is a three-sided achene, often with a round tubercle on one or all three sides. The genus was first described by Carl Linnaeus in 1753. Within the family Polygonaceae, it is placed in the subfamily Polygonoideae. The genus Emex was separated from Rumex by Francisco Campderá in 1819 on the basis that it was polygamous (i.e. had both bisexual and unisexual flowers on the same plant). However, some species of Rumex subg. Acetosa also have this characteristic, and most other features that are supposed to distinguish Emex are found in species of Rumex. Accordingly, in 2015, Schuster et al. demoted Emex to a subgenus of Rumex. Within the subfamily Polygonoideae, Rumex is placed in the tribe Rumiceae, along with the two genera Oxyria and Rheum. It is most closely related to Rheum. As of March 2019, Plants of the World Online accepted the following species. A large number of hybrids are also recorded. These plants have many uses. Broad-leaved dock (Rumex obtusifolius) used to be called butter dock because its large leaves were used to wrap and conserve butter.