''Duma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 trees ...

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 th ...

s in the family

Polygonaceae The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus ''Polygonum'', and was first used by Antoine Laurent de Jussieu in 1789 ...

, subfamily

Polygonoideae Polygonoideae is a subfamily of plants in the family Polygonaceae. It includes a number of plants that can be highly invasive, such as Japanese knotweed, ''Reynoutria japonica'', and its hybrid with '' R. sachalinensis'', ''R.'' × ''bohemica'' ...

. The genus was separated from ''

Muehlenbeckia ''Muehlenbeckia'' or maidenhair is a genus of flowering plants in the family Polygonaceae. It is native to the borders of the Pacific, including South and North America, Papua New Guinea and Australasia. It has been introduced elsewhere, includin ...

'' in 2011. The native range of the genus is Australia.

Description

Species of ''Duma'' are

s, 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 Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

. Staminate flowers have eight

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 filame ...

s and a rudimentary or missing

pistil Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

; pistillate flowers have

staminode In botany, a staminode is an often rudimentary, sterile or abortive stamen, which means that it does not produce pollen.Jackson, Benjamin, Daydon; ''A Glossary of Botanic Terms with their Derivation and Accent''; Published by Gerald Duckworth & Co. ...

s. The fruit is in the form of an ovoid or three-angled

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

, which is smooth and shiny.

Taxonomy

The genus ''Duma'' was created by

Tanja Schuster Tanja Magdalena Schuster is a taxonomist from Kaindorf, Austria and the first Pauline Ladiges Plant Systematics Fellow, holding a joint position with the School of Biosciences, University of Melbourne, Victoria, Australia, and the National Herbariu ...

in 2011 for some species previously placed in ''

'', but which were shown by

molecular phylogenetic 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 ...

studies to form a distinct clade. The name is derived from the Latin for "thorn-bush". ''Duma'' is placed in the tribe Polygoneae of the subfamily

. Within the tribe, it is most closely related to the genera '' Atraphaxis'' and ''

Polygonum ''Polygonum'' is a genus of about 130 species of flowering plant in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In the ...

'', forming the so-called "DAP clade", and is not so closely related to ''Muehlenbeckia''.

Species

, three species were accepted by

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

: *''

Duma coccoloboides A duma (russian: дума) is a Russian assembly with advisory or legislative functions. The term ''boyar duma'' is used to refer to advisory councils in Russia from the 10th to 17th centuries. Starting in the 18th century, city dumas were for ...

'' (J.M.Black) T.M.Schust. (syn. ''Muehlenbeckia coccoloboides'') *''

Duma florulenta ''Duma florulenta'' (Synonym (taxonomy), synonym ''Muehlenbeckia florulenta''), commonly known as tangled lignum or often simply lignum, is a plant native to inland Australia. It is associated with wetland habitats, especially those in arid and ...

'' (Meisn.) T.M.Schust. (syn. ''Muehlenbeckia florulenta'') *''

Duma horrida A duma (russian: дума) is a Russian assembly with advisory or legislative functions. The term ''boyar duma'' is used to refer to advisory councils in Russia from the 10th to 17th centuries. Starting in the 18th century, city dumas were for ...

'' (H.Gross) T.M.Schust. (syn. ''Muehlenbeckia horrida'')

References

{{Taxonbar, from1=Q18340651 Polygonoideae Polygonaceae genera Dioecious plants