Duma (plant)

Species of Duma are shrubs, with many flexible branches, whose tips are thornlike. They have white to greyish bark. The leaves are longer than wide, with a very small curved spine at the tip. The flowers are without stalks (petioles). Plants are dioecious. Staminate flowers have eight stamens and a rudimentary or missing pistil; pistillate flowers have staminodes. The fruit is in the form of an ovoid or three-angled achene, which is smooth and shiny.^[3]

The genus Duma was created by Tanja Schuster in 2011 for some species previously placed in Muehlenbeckia, but which were shown by molecular phylogenetic studies to form a distinct clade. The name is derived from the Latin for "thorn-bush".^[3] Duma is placed in the tribe Polygoneae of the subfamily Polygonoideae. Within the tribe, it is most closely related to the genera Atraphaxis and Polygonum, forming the so-called "DAP clade", and is not so closely related to Muehlenbeckia.^[2]

As of March 2019^[update], three species were accepted by Plants of the World Online:^[1]

• Duma coccoloboides (J.M.Black) T.M.Schust. (syn. Muehlenbeckia coccoloboides)
• Duma florulenta (Meisn.) T.M.Schust. (syn. Muehlenbeckia florulenta)
• Duma horrida (H.Gross) T.M.Schust. (syn. Muehlenbeckia horrida)