Flacourtia rukam

Flacourtia rukam

The rukam or Indian prune (Flacourtia rukam Zoll. & Moritzi 1846) is an arboreal species belonging to the Salicaceae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Subkingdom Tracheobionta,
Spermatophyta Superdivision,
Division Magnoliophyta,
Class Magnoliopsida,
Subclass Dilleniidae,
Salicales Order,
Family Salicaceae,
Genus Flacourtia,
Species F. rukam.
The terms are synonymous:
– Flacourtia cataphracta Blume;
– Flacourtia edulis Griff.;
– Flacourtia euphlebia Merr.;
– Flacourtia megaphylla Ridl.;
– Flacourtia peninsula Elmer;
– Flacourtia peninsularis Elmer;
– Flacourtia peninsularis Elmer ex Merr.;
– Flacourtia sulcata Elmer;
– Hisingera grandifolia Turcz..
Within this species the following varieties are recognised:
– Flacourtia rukam var. micronesica Fosberg & Sachet;
– Flacourtia rukam var. rukam.

Etymology –
The term Flacourtia is in honor of the Frenchman Étienne de Flacourt (1607-1660) who was Governor of Madagascar.
The specific epithet rukam comes from the Malay vernacular name.

Geographic Distribution and Habitat –
Flacourtia rukam is a plant native to the insular south-eastern Asia of Melanesia and China (Guangdong, Guangxi, Hainan and Yunnan) and present in Indonesia, Malaysia, Papua New Guinea, Taiwan, Thailand and Vietnam; from here the plant spread to continental south-eastern Asia, India and Polynesia.
Its natural habitat is that of humid evergreen forests up to around 1500 m above sea level, often along the banks of watercourses but it is also cultivated for its edible fruits.

Description –
Flacourtia rukam is a generally dioecious, evergreen tree, very branched from the base.
The trunk is 5-18 m high and up to 30 cm in diameter, equipped with robust simple or bifurcated thorns, up to 10 cm long, present even on older branches, sometimes absent in cultivated plants.
The leaves are carried by a petiole about 0.5 cm long, are simple, alternate, oblong-elliptical with slightly toothed margin and long thinned apex, 6-13 cm long and 3-6 cm wide, glabrous, of dark green above, lighter below; the young leaves are drooping, ranging from deep pink to red-brown in colour.
The inflorescences are short, slightly pubescent axillary racemes bearing tiny unisexual, rarely bisexual, flowers without greenish yellow petals.
The fruits are globose, rounded berries, 1.5-2.5 cm in diameter, with persistent styles at the apex, pale green to pink in colour, to dark purple when ripe, with juicy and acidic whitish pulp.
Inside there are usually from 4 to 7 flattened seeds of irregular shape of about 8×5 mm.

Cultivation –
Flacourtia rukam is an often thorny tree which, in addition to growing in its natural state, is cultivated in some areas of the tropics, particularly in Asia, for its edible fruits.
The plant grows best in humid tropical conditions up to an altitude of 1,500 meters above sea level and prefers a full sun position in fertile, well-drained soil.
It is a species suitable for humid tropical and subtropical climate zones, its cultivation can be attempted in milder temperate-warm ones, where temperature values around 0 °C are exceptional and very short-lived events. It requires exposure in full sun or partial shade and is not particularly demanding regarding soils, even poor ones, kept almost constantly humid, even if it grows best in sandy and acidic ones.
However the tree appears to be quite adaptable to a wide range of temperatures, precipitation and soil conditions.
The plants are generally dioecious, although monoecious forms are occasionally found; so while female trees often fruit in the absence of a male plant, both male and female plants should be grown for better yields.
The plant reproduces easily by seed, so much so that it has naturalized in many tropical areas where it has been introduced, in draining soil kept humid at a temperature of 22-24 °C, with germination times of 6-8 weeks, by layering or through root suckers that it usually produces.

Customs and Traditions –
Flacourtia rukam is a plant known by various common names; among these we report the following: Indian prune, rukam (English); from ye ci li mu (Chinese); prunier de Chine, prunier malgache (French); rukam gajah, rukam manis, rukem (Malay); ciruela de Madagascar (Spanish); Madagaskarpflaume (German); khrop dong, ta khop thai (Thai); mung guan ru’ng (Vietnamese).
The fruits are edible even if the acidulous and astringent pulp is not usually consumed raw, even if crushing the fruit, for example between the hands, seems to reduce the astringency, but it is used for preserves and condiments; the young shoots are consumed in some places both raw and cooked as a vegetable.
The wood, which is particularly hard, is used in construction and for commonly used objects. Leaves, fruits and roots are used in traditional medicine for various pathologies.

Preparation Method –
Flacourtia rukam is a plant that is collected in its natural state or cultivated for various uses, such as food, medicine and for its wood.
The fruits are eaten raw or cooked. The ripe fruits are purple, juicy and sub-acid, they are often eaten even in the wild.
Rolling the fruit between your palms just before eating reduces the fruit’s natural astringency.
The fruit is also used to prepare jams, jellies and preserves.
The young shoots, a beautiful red, are eaten raw in salads and side dishes.
In the medicinal field, the immature fruit is rich in tannins and is used to prepare a traditional medicine to treat diarrhea and dysentery.
The juice of the leaves is applied on the inflamed eyelids.
A decoction of the root is taken by women after giving birth.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/3676366/original.JPG
– https://sweetgum.nybg.org/images3/4095/757/04710815.jpg

Attention: Pharmaceutical applications and food uses are indicated for informational purposes only, they do not represent in any way a medical prescription; we therefore decline any responsibility for their use for healing, aesthetic or food purposes.