''Myriocarpa'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of woody plants in the family

Urticaceae The Urticaceae are a family, the nettle family, of flowering plants. The family name comes from the genus ''Urtica''. The Urticaceae include a number of well-known and useful plants, including nettles in the genus ''Urtica'', ramie (''Boehmeria ...

. Species in the genus range in size from

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 to 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 and are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Central and South America. ''Myriocarpa'' is characterized by long pendulous string-like female

inflorescences In botany, an inflorescence is a group or cluster of flowers arranged on a plant's 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 main axis ( pe ...

of apparently naked

flowers Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

and stems which release a watery

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well. In nature, latex is found as a wikt:milky, milky fluid, which is present in 10% of all floweri ...

when cut. Estimates for the diversity of the genus range from five to eighteen

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

.Burger, W. 1977. Myriocarpa, Flora Costaricensis. Fieldiana, Botany 40: 237-240.Friis, I. 1989. The Urticaceae: a systematic review. In P. R. Crane and S. Blackmore ds. Evolution, systematics, and fossil history of the Hamamelidae, vol. 2, Systematics Association Special Volume 40B, 285–308. Oxford Science Publications, Oxford, UK Research for Flora Mesoamericana indicates that there are probably fifteen to twenty species. The genus was described by

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...

in 1846Bentham, G. 1846. The botany of the voyage of H.M.S. Sulphur 168, t. 55. based on Colombian specimens of '' Myriocarpa stipitata'' collected by Mss. Barclay. Weddell placed ''Myriocarpa'' in the

tribe BoehmerieaeWeddell, H. A. 1856. Urera. In G. Baudry and J. Baudry ds. Monographie de la famille des Urticacées. 484–490. G. and J. Baudry, Paris, France.Weddell, H. A. 1869. Myriocarpa. In A. De Candolle d. Prodromus systematis naturalis regni vegetabilis 16, 23533–23536. Paris, France. despite its anomalous pubescence,

cystolith Cystolith (Gr. "cavity" and "stone") is a botanical term for outgrowths of the epidermal cell wall, usually of calcium carbonate but sometimes of silicon dioxide also, formed in a cellulose matrix in special cell (biology), cells called lithocys ...

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

and wood anatomy. In his review of the Urticaceae, Friis retained its position within the Boehmerieae, presumably because its position in any other Urticaceae tribe would be equally ambiguous. The position of ''Myriocarpa'' within the Boehmerieae is not supported by recent

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses of trnL-F sequence dataMonro, 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 Am. J. Botany 93: 426-441 that recovered ''Myriocarpa'' within a strongly supported

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

including both the Urticeae and Lecantheae tribes. Its position within either one of these tribes however, is unresolved. Based on hair, leaf and flower morphology, Myriocarpa could equally well be placed in the Lecantheae (absence of hooked hairs) or the Urticeae (alternate leaves, pistillodes not ejecting the

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 ...

) and further research, both

molecular A molecule is a group of two or more atoms that are held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, ...

and morphological, is warranted. The last major revision of the genus, at which time six species were recognized, was that of

Hugh Algernon Weddell Hugh Algernon Weddell (22 June 1819 – 22 July 1877) was a physician and botanist, specialising in South American flora. Weddell was born at Birches House, Painswick near Gloucester, England, but was raised in France and educated at th ...

. Since this revision ''Myriocarpa'' has attracted little taxonomic interest outside of floristic treatments,Standley, P. C., & J. A. Steyermark. 1952. Pilea, Flora of Guatemala.Fieldiana, Botany 3: 404–406. despite its unusual female inflorescence morphology and ambiguous position within the Urticaceae and currently a total of 24 species names have been published.International Plant Names Index. 2006. Available at website http://www.ipni.org ccessed 1 July 2006

References

{{Taxonbar, from=Q6948249 Urticaceae Urticaceae genera