monotypic genus
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...
of flowering plants in the
citrus
''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is nati ...
family,
Rutaceae
The Rutaceae is a family, commonly known as the rueRUTACEAE in BoDD – Botanical Der ...
, containing the single species ''Merrillia caloxylon''. Its
English language
English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to t ...
common names include flowering merrillia, katinga, and Malay lemon. 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 called ''ketenggah'' and ''kemuning gajah''.Lim, T. K. (2012) ''Merrillia caloxylon''. In: ''Edible Medicinal And Non-Medicinal Plants''. Springer Netherlands. 890-92. The species is native to Malaysia,
Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
.
This species is a member of the Rutaceae subfamily
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 Sou ...
, which includes the genus ''
Citrus
''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is nati ...
''. It has been placed as the only genus and species in the subtribe Merrilliinae, which are known technically as the large-fruited remote citroid fruit trees.Citrus Variety Collection. University of California, Riverside. The genus is sunk into ''
Murraya
''Murraya'' () is a genus of flowering plants in the citrus family, Rutaceae. It is distributed in Asia, Australia, and the Pacific Islands. but accepted in a 2021 classification of the Rutaceae.
Description
This species is a
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 ...
often reaching up to 20 meters tall, sometimes approaching 30 meters. One report from 1932 mentions a specimen collected from a tree 33.6 meters tall. If the report is valid it would be the largest tree of the Aurantioideae. The trunk has a light, flaking
bark
Bark may refer to:
* Bark (botany), an outer layer of a woody plant such as a tree or stick
* Bark (sound), a vocalization of some animals (which is commonly the dog)
Places
* Bark, Germany
* Bark, Warmian-Masurian Voivodeship, Poland
Arts, en ...
. The leaves can exceed 20 centimeters in length,Citrus Variety Collection: ''Merrillia caloxylon''. University of California, Riverside. and each is made up of 5 to 13 leaflets up to about 10 centimeters long, the basal ones smaller than the others. They are thin, bright green, and somewhat lance-shaped with triangular bases. The flowers are solitary, paired, or borne in
panicle
A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is ...
s. They are white to yellow-green and trumpet-shaped with petals up to 1.8 centimeters long. The oblong fruit is up to 11 centimeters long by 7.5 wide. It has a warty
peel
Peel or Peeling may refer to:
Places Australia
* Peel (Western Australia)
* Peel Island, Queensland
*Peel, New South Wales
* Peel River (New South Wales)
Canada
* Peel Parish, New Brunswick
* Peel, New Brunswick, an unincorporated communi ...
over a centimeter thick. It is green, turning yellow with maturity. The fruit contains a tasteless, fibrous, olive-green pulp.
The native habitat of the tree includes primary and secondary tropical forest.
Uses
The species has been noted for its
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of ligni ...
, which is bright yellow with dark brown streaks. It is a hard wood used historically in Malaysia to make
walking stick
A walking stick or walking cane is a device used primarily to aid walking, provide postural stability or support, or assist in maintaining a good posture. Some designs also serve as a fashion accessory, or are used for self-defense.
Walking s ...
s and
kris
The kris, or ''keris'' in the Indonesian language, is an asymmetrical dagger with distinctive blade-patterning achieved through alternating laminations of iron and nickelous iron (''pamor''). Of Javanese origin, the kris is famous for its disti ...
handles. It was also good for making
furniture
Furniture refers to movable objects intended to support various human activities such as seating (e.g., stools, chairs, and sofas), eating ( tables), storing items, eating and/or working with an item, and sleeping (e.g., beds and hammocks) ...
and boxes. The species was too rare to provide a supply of commercial timber.
Several
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 ...
alkaloid
Alkaloids are a class of basic
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Th ...
yuehchukene
Yuehchukene is a dimeric indole alkaloid natural product that possesses anti-fertility and estrogenic activities. Yuehchukene is isolated from the roots of ''Murraya paniculata'' and other species of the plant genus '' Murraya''. Its natural abun ...
has been found in the bark; it is a compound well known from the related genus ''