The micrantha is a wild
citrus from the
papeda group, native to southern
Philippines, particularly islands of
Cebu and
Bohol. Two
varieties are recognized: small-flowered papeda (''C. hystrix'' var. ''micrantha''), locally known as ''biasong'', and small-fruited papeda (''C. hystrix'' var. ''microcarpa'') or ''samuyao''.
Long viewed as a separate species, ''C. micrantha'', it is now generally viewed to fall within ''
Citrus hystrix'', but genomic data on the latter is insufficient for a definitive conclusion. A micrantha was one of the
progenitor
In genealogy, the progenitor (rarer: primogenitor; german: Stammvater or ''Ahnherr'') is the – sometimes legendary – founder of a family, line of descent, clan or tribe, noble house, or ethnic group..
Ebenda''Ahnherr:''"Stammvater eines G ...
species of some varieties of
lime.
Description
The micrantha was first described to Western science in 1915 by
Peter Jansen Wester, who worked for the Philippine Bureau of Agriculture at the time.
Biasong
Wester collected ripe fruit specimens of biasong (small-flowered papeda, ''Citrus hystrix'' var. ''micrantha'') on islands of Cebu, Bohol,
Dumaguete,
Negros, and in the
Zamboanga and
Misamis provinces in
Mindanao. The fruits were collected throughout the year, indicating that the plant is ever-bearing. Biasong is characterized by small flowers (thus the "small-flowered" moniker) with fewer
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 than other papedas and oblong-obovate, few-
locule
A locule (plural locules) or loculus (plural loculi) (meaning "little place" in Latin) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus).
In angiosperms (flowering plants), the term ''locule'' usu ...
d fruits. Inhabitants did not use the fruits for food, but for hair-washing, and it had little economic importance.
[
Biasong's aroma is similar to that of the samuyao variety of micrantha. The tree reaches in height. Leaves are long, wide, broadly elliptical to ovate, crenate, thin, with base rounded or broadly acute; apex acutely blunt pointed. Petioles are long, broadly winged, up to wide, with wings (phyllodes) sometimes larger than the leaf. Flowers are small, four-petaled, white with a thin purple edge, in diameter, forming ]cymes
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on ...
of two to five. There are 15 to 17 equal 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. The ovary is obovoid, with 6 to 8 slender, distinct locule
A locule (plural locules) or loculus (plural loculi) (meaning "little place" in Latin) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus).
In angiosperms (flowering plants), the term ''locule'' usu ...
s. Fruits are obovate to oblong-obovate, long, with diameter of , averaging in weight; their skin is rather thick, lemon-yellow, fairly smooth or with transverse corrugations; the pulp is juicy, grayish and acid, while juice cells are short and blunt to long, long, slender and pointed, sometimes containing a minute, greenish nucleus. They have numerous flat, pointed, reticulate seeds.[
]
Samuyao
Wester collected ripe samuyao (small-fruited papeda, ''Citrus hystrix'' var. ''microcarpa'') fruit specimens from cultivation in Cebu and Bohol in June, and from November to February. Samuyao is rather smaller than biasong, with trees attaining 4.5 meters. It has small, thin leaves and flowers comparable in size to biasong. The fruit, 15–20 mm in diameter, is likely to be the smallest in the whole genus.[ Wester also recorded a somewhat more vigorous variety, called "samuyao-sa-amoo" in Bohol, with slightly larger fruits; there is a possibility that this species was actually ''Limonellus aurarius'', described by Georg Eberhard Rumphius back in 1741 in a nearby area, although his description also fits a number of related species.][
Wester gave the botanical description:][
Clear, intensely fragrant oil can be produced from the samuyao peel, and it has been used as a hair fragrance by women who live where it grows.]
Toxicity
The micrantha contains a significant amount of bergapten, a linear furanocoumarin well known for its phototoxic effects.[ Cited i]
CIR 2013
[ Cited i]
CIR 2013
a potentially severe skin inflammation. In these cases, the primary causal agent is believed to be bergapten.
Hybrids
The Key lime (''Citrus aurantifolia'') is a hybrid of the micrantha and the citron. It, in turn, has been crossed with a lemon to produce the Persian lime
Persian lime (''Citrus'' × ''latifolia''), also known by other common names such as seedless lime, Bearss lime and Tahiti lime, is a citrus fruit species of hybrid origin, known only in cultivation. The Persian lime is a triploid cross between ...
(''C. latifolia''). There are lumias that are distinct micrantha/citron hybrids, such as the Pomme d'Adam, while other lumias, like the Borneo lemons, are micrantha/citron/pomelo tri-species hybrids.
References
External links
Searching for the Elusive Samuyao
"Our Philippine Trees" blog
"Our Philippine Trees" blog
{{Taxonbar, from=Q20704151
Micrantha
Flora of the Philippines
Plants described in 1915