| Excoecaria agallocha | |
|---|---|
_W_IMG_6929.jpg) | |
| Excoecaria agallocha inKrishna Wildlife Sanctuary,Andhra Pradesh,India | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Euphorbiaceae |
| Genus: | Excoecaria |
| Species: | E. agallocha |
| Binomial name | |
| Excoecaria agallocha | |
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Excoecaria agallocha, amangrovespecies, belongs to thegenusExcoecaria of thefamilyEuphorbiaceae. The species has many common names, includingblind-your-eye mangrove,[1]blinding tree,[citation needed]buta buta tree,[2]milky mangrove,[3]poisonfish tree, andriver poison tree.[4] Most of the names refer to its toxic properties or its propensity to cause blindness when itslatex comes into contact with the eyes.
This plant grows in saline or brackish water intropicalmangrove forests, in a distribution bounded to the west byIndia, to the north byBangladesh, to the south byAustralia. Within Australia, it thrives from northernNew South Wales along the northern coastline around toWestern Australia.
Mangrove swamps form a type of coastalwetland found in the tropics and subtropics.[5] Within a mangrove forest, the most salt-tolerant species occur near the ocean.Excoecaria agallocha, known as a back mangrove, is found at higher elevations back away from the ocean where salinity is lower.[6] Mangroves of this plant surround the ancientThillai Chidambaram Temple inTamil Nadu.
This small tree species may grow up to 15 m high. Trees are either male or female (dioecious). Male flowers form drooping tassels, while female flowers appear as shorter spikes. Pollinators such as bees commonly visit the flowers. The fruit is a small dark capsule.[7]
The milkylatex ofExcoecaria agallocha is very poisonous and powerfully irritant, which is not unusual in milky species of plant in the family Euphorbiaceae. Contact with skin causes irritation and rapid blistering; slight contact with eyes can cause temporary blindness, hence the common names that refer to blindness. Even the generic name is from the Latin for "blinder".
William Bligh in his bookVoyage to the South Sea mentioned that he was already aware of this hazard when he embarked on the voyage that ended in the notoriousmutiny on the Bounty, having learned of it in 1777 from CaptainJames Cook during the time that he served as Cook'ssailing master. Several of the men that Cook had sent ashore to cut wood had been blinded for a time. He accordingly instructed his men not to cut that type of tree when he sent them ashore in Tahiti to gather wood and water in 1789.[8] It was just as well that he did so, because even the smoke from the burning wood is poisonous and can harm the eyes, so it would not have been useful as fuel.[9]
Excoecaria agallocha, amangrovespecies, belongs to thegenusExcoecaria of thefamilyEuphorbiaceae.
The latex produced byE. agallocha contains a variety ofphorbol-like toxins such as excoecariatoxin which are powerful irritants to the skin, eyes and mucous membranes.[10][11]
Despite the powerful chemical defense mechanisms of this plant,E. agallocha is the sole food source for thelarvae of the mangrove jewel bug (Calliphara nobilis), aphytophagous species ofjewel bug found intropicalmangrove forests in some parts of Asia.[12][13] Like many other species ofaposematic scutellerids,[14][15]C. nobilis is able to sequester chemical compounds from its host plants that are toxic to their predators, and use them towards its own defenses. These chemical compounds are concentrated and stored in a pair of scent glands located on themetathorax of the adults andnymphs. When these insects are threatened or handled, they can secrete an irritating and toxic fluid from these glands as a deterrent to potential predators.
Even dried and powdered leaves retain the poison and can kill fish very quickly or be used on a poison dart.[7]
Excoecaria agallocha has been found to have various medicinal and pharmacological benefits, including the treatment for epilepsy, ulcers, leprosy, rheumatism, and paralysis.[16] This plant species appears to be quite chemically complex.[17]
