''Micromelum'' is a genus of eight species of flowering plants in the family

Rutaceae The Rutaceae is a family, commonly known as the rueRUTACEAE
in BoDD – Botanical Der ...

Description

The genus includes evergreen and deciduous shrubs and

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, including only woody plants with secondary growth, plants that are ...

s. The leaves are glandular and aromatic, containing essential oils. They are alternately arranged. They are usually

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

, divided into up to 23 leaflets, except for ''M. diversifolium'', which sometimes has undivided leaf blades. The leaflet edges are smooth or toothed. There are sometimes glandular

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

is a large panicle, sometimes flat-topped like a corymb, growing from the leaf axils or at the ends of branches. The flowers have five narrow petals in shades of green, white, or yellow, borne in a hairy, cup-like calyx with five lobes or five separate

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s. The odor of the flowers has been described as "malodorous" and "foetid". There are 10 stamens and 1 to 5 styles. The genus is noted for the unusual curving or twisting of the chambers in the ovary. The fruit is a berry up to a centimeter long. It is yellow, orange, or red, and sometimes fleshy, but it lacks the

pulp Pulp may refer to: * Pulp (fruit), the inner flesh of fruit Engineering * Dissolving pulp, highly purified cellulose used in fibre and film manufacture * Pulp (paper), the fibrous material used to make paper * Molded pulp, a packaging material ...

present in some related fruits, notably citrus. The peel is gland-dotted. Each fruit has 1 to 3 seeds. The plants vary in form, with '' M. hirsutum'' being a low shrub sometimes less than a tallKey to the species of ''Micromelum''.
Chapter 3: The Botany of ''Citrus'' and its Wild Relatives. and '' M. integerrimum'' being a tree which can exceed in height.

Taxonomy

The genus ''Micromelum'' was first formally described in 1825 by

Carl Ludwig Blume Charles Ludwig de Blume or Karl Ludwig von Blume (9 June 1796, Braunschweig – 3 February 1862, Leiden) was a German- Dutch botanist. He was born at Braunschweig in Germany, but studied at Leiden University and spent his professional life wor ...

in '' Bijdragen tot de Flora van Nederlandsch Indie'' and the first species described was ''Micromelum pubescens'', now regarded as a synonym of '' Micromelum minutum''. There are several subfamilies in the citrus family, with genus ''Citrus'' classified in the

Aurantioideae Aurantioideae (sometimes known as Citroideae) is the subfamily within the rue and citrus family (Rutaceae) that contains the citrus. The subfamily's center of diversity is in the monsoon region of eastern Australasia, extending west through South ...

. ''Micromelum'' belongs to the other tribe in this subfamily,

Clauseneae Clauseneae is one of the two tribes of the flowering plant family Rutaceae, subfamily Aurantioideae, the other being Citreae, which includes ''Citrus''. References * Wight A wight (Old English: ''wiht'') is a mythical sentient being, ofte ...

. It is the only genus of the subtribe Micromelinae that are known technically as the "very remote citroid fruit trees".Swingle, W. T., rev. P. C. Reece
Chapter 3: The Botany of ''Citrus'' and its Wild Relatives.
In: ''The Citrus Industry'' vol. 1. Webber, H. J. (ed.). Berkeley: University of California Press. 1967. ''Micromelum'' includes eight species distributed in Asia, Australia, and the Pacific Islands.''Micromelum''.
Flora of China.
College of Natural and Agricultural Sciences. University of California, Riverside.

Species list

The following is a list of species and varieties accepted at the Plants of the World Online as at July 2020: * '' Micromelum compressum''

Blanco Blanco (''white'' or ''blank'' in Spanish) or Los Blancos may refer to: People *Blanco (surname) Fictional characters *Blanco, a hobbit in J. R. R. Tolkien's Middle-earth * Blanco Webb, character in the BBC sitcom ''Porridge'' * El Blanco, albin ...

– Vietnam * '' Micromelum coriaceum''

Seem. Berthold Carl Seemann (25 February 1825, in Hanover, Germany – 10 October 1871, in Nicaragua, Central America), was a German botanist. He travelled widely and collected and described plants from the Pacific and South America. In 1844 he trave ...

– New Caledonia * '' Micromelum diversifolium''

Miq. Friedrich Anton Wilhelm Miquel (24 October 1811 – 23 January 1871) was a Dutch botanist, whose main focus of study was on the flora of the Dutch East Indies. Early life Miquel was born in Neuenhaus and studied medicine at the University of Groni ...

* '' Micromelum glanduliferum'' B.Hansen – Laos, Thailand * '' Micromelum hirsutum''

Oliv. Daniel Oliver, FRS (6 February 1830, Newcastle upon Tyne – 21 December 1916) was an English botanist. He was Librarian of the Herbarium, Royal Botanic Gardens, Kew from 1860–1890 and Keeper there from 1864–1890, and Professor of Botany at ...

– Bangladesh, Laos, Malaya, Myanmar, Vietnam * '' Micromelum integerrimum'' (

Roxb. William Roxburgh FRSE FRCPE FLS (3/29 June 1751 – 18 February 1815) was a Scottish surgeon and botanist who worked extensively in India, describing species and working on economic botany. He is known as the founding father of Indian botany. H ...

DC. Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple of years de Candolle ...

)

Wight A wight (Old English: ''wiht'') is a mythical sentient being, often undead. In its original use the word ''wight'' described a living human being, but has come to be used in fictional works in the fantasy genre to describe certain immortal bein ...

Arn. George Arnott Walker Arnott of Arlary (6 February 1799 – 17 April 1868) was a Scottish botanist. Early life George Arnott Walker Arnott was born in Edinburgh in 1799, the son of David Walker Arnott of Arlary. He attended Milnathort Parish ...

ex M.Roem. – Andaman Is., Cambodia, China South-Central, China Southeast, East Himalaya, Hainan, Laos, Myanmar, Nepal, Philippines, Thailand, Tibet, Vietnam * '' Micromelum minutum'' (

G.Forst. Johann George Adam Forster, also known as Georg Forster (, 27 November 1754 – 10 January 1794), was a German naturalist, ethnologist, travel writer, journalist and revolutionary. At an early age, he accompanied his father, Johann Reinhold F ...

) Wight & Arn. – Assam, Bangladesh, Cambodia, China South-Central, China Southeast, Fiji, Hainan, Laos, Lesser Sunda Is., Malaya, Myanmar, New Caledonia, Niue, Samoa, Solomon Is., Thailand, Tonga, Vanuatu, Vietnam, Wallis-Futuna Is., Australia ** ''Micromelum minutum'' var. ''ceylanicum'' B.C.Stone – Sri Lanka * '' Micromelum scandens'' Rech. – Bismarck Archipelago

Chemistry

''M. minutum'' is used as a

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...

in Fiji, and in

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

it is used to treat

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

and

ringworm Dermatophytosis, also known as ringworm, is a fungal infection of the skin. Typically it results in a red, itchy, scaly, circular rash. Hair loss may occur in the area affected. Symptoms begin four to fourteen days after exposure. Multiple ar ...

.Ito, C., et al. (2000)
Chemical constituents of ''Micromelum minutum''. Isolation and structural elucidation of new coumarins.
''Chemical and Pharmaceutical Bulletin - Tokyo'' 48(3), 334-38. ''M. integerrimum'' has been used in China to treat

dysentery Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...

and arthritis.He, H. P., et al. (2001)
Three new coumarins from ''Micromelum integerrimum''.
''Chinese Chemical Letters'' 12(7) 603-06. The chemistry of these plants has been studied, with several known and new

coumarin Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...

s isolated. One such coumarin from ''M. integerrimum'', micromelin, appears to have anticancer properties.

References

{{Taxonbar, from=Q9032437 Aurantioideae genera Aurantioideae