''Urera'' is a genus of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the nettle family, Urticaceae. It has a pantropical distribution.Steinmann, V. W. (2005)
Four new neotropical species and a new combination of ''Urera'' (Urticaceae).
''Acta Botánica Mexicana'' (71), 19-43.

Description

''Urera'' are

liana A liana is a long-Plant stem, stemmed Woody plant, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the Canopy (biology), canopy in search of direct sunlight. T ...

s,''Urera''.
Flora Zambesiaca.

shrub A shrub or 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 by their multiple ...

s, and small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s. Climbing species root along the stems and can reach the crowns of the trees they use for support. Some are spiny. They almost always have urticating hairs, often on bumps in the epidermis. These are stiff, stinging

trichome Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

s with swollen bases. The leaves are variable in shape and venation, and help in the identification of species. Also useful is the varying appearance and arrangement of cystoliths on the leaf surface. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a divided, branching

panicle In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...

of flowers. Most species are

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, but a few are

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...

. Most species have male flowers with either four or five

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s and

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s. Female flowers generally have four uneven, free to mostly fused tepals. The fruit is an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

covered in orange or red flesh.

Systematics and taxonomy

The genus ''Urera'' was first described by Charles Gaudichaud-Beaupré in 1826 in his review of the studies done on Louis de Freycinet's voyage of the '' Uranie''. He noted its distinctness, proposing the

subtribe Subtribe is a taxonomic category ranking which is below the rank of tribe and above genus. The standard suffix for a subtribe is -ina (in animals) or -inae (in plants). The first use of this word dates back to the late 19th century. An example of ...

Urereae. This was later raised to the rank of

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

, and subsequently merged into Urticeae.Friis, I. (1989): The Urticaceae: a systematic review. ''In'': Crane, P. E. & Blackmore, S. (eds.): ''Evolution, systematics, and fossil history of the Hamamelidae'' (Vol. 2): 285–308. ''Systematics Association Special Volume'' 40B. Oxford Science Publications, Oxford, UK. No botanical

monograph A monograph is generally a long-form work on one (usually scholarly) subject, or one aspect of a subject, typically created by a single author or artist (or, sometimes, by two or more authors). Traditionally it is in written form and published a ...

s have been devoted to ''Urera'' since 1869. Knowledge of the systematics of the genus has accumulated mainly from new descriptions of species and floristic accounts. About 113 species epithets have been published for the genus.

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

currently accepts 28 species. Many species have been transferred to other genera, including '' Boehmeria'', '' Dendrocnide'', '' Girardinia'', '' Gyrotaenia'', '' Laportea'', '' Obetia'', and '' Scepocarpus''. Other estimates for the number of valid species in ''Urera'' range up to 75. The genus is not well known, with current knowledge dependent mainly on outdated studies, and there is little agreement regarding its

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

. Analysis of '' trnL-F''

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

data suggests that ''Urera'' could be sister to '' Poikilospermum'' within the Urticaceae.Monro, A. K. (2006)
The revision of species-rich genera: a phylogenetic framework for the strategic revision of ''Pilea'' (Urticaceae) based on CPDNA, NRDNA and morphology.
'' American Journal of Botany'' 93(3): 426-41.

Species

28 species are accepted. *'' Urera acuminata'' *'' Urera altissima'' *'' Urera aurantiaca'' *'' Urera baccifera'' ( L.) Gaudich. ex Wedd., 1852 – guaritoto, scratchbush *'' Urera capitata'' *'' Urera caracasana'' ( Jacq.) Gaudich. ex Griseb. – flameberry *'' Urera elata'' *'' Urera expansa'' ( Sw.) Griseb. *'' Urera fenestrata'' *'' Urera filiformis'' *'' Urera glabriuscula'' *'' Urera gravenreuthii'' *'' Urera guanacastensis'' *'' Urera kaalae'' Wawra – ''Opuhe'' (

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

in Hawaii) *'' Urera keayi'' *'' Urera killipiana'' *'' Urera laciniata'' *'' Urera lianoides'' *'' Urera lobulata'' *'' Urera martiniana'' *'' Urera nitida'' *'' Urera pacifica'' *'' Urera simplex'' *'' Urera talbotii'' *'' Urera verrucosa'' – ''chichicastle'', ''mala mujer''

Formerly placed here

*'' Touchardia sandwicensis'' – hopue, ''Ōpuhe'' (

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

) (as ''Urera sandwicensis'' , ''U. glabra'' , and ''U. konaensis'' )

Description

Systematics and taxonomy

Species

Formerly placed here

References

Further reading