Easily mistaken for :
(African) Tamarix (Tamarix africana), but that has much whiter flowers with smaller areas of pinkishness, and is much less abundant than (French) Tamarix (Tamarix gallica) being extant in only very few hectads in the UK. African Tamarix never sets seed in the UK, it is always planted.
Uniquely identifiable characteristics
Distinguishing Feature : The fine filigree featheriness of the foliage and the catkin-like panicles of pinkish flowers held very close to the stems. Tamarisk as in Tamarix gallica is deciduous as are three other species, but many other species of Tamarix are evergreen.
Tamarisk species (of which there are 50 to 60 in the World) are salt-loving tall shrubs or short trees, growing from 1m to 18m high. The leaves are tiny, green, over-lapping, and similar to those of Cypresses, hence the other common name 'Salt Cedar' although it belongs to neither the Pine Family (Pinaceae) nor to the Cypress Family (Cupressaceae). But un-like the leaves on Cypresses, the leaves (which look like tiny scales) on Tamarisks are alternate. Tamarisk does not bear cones but rather a capsule that is full of tiny seeds with a tiny pappus and are borne by the wind.
Indigenous to Saudi Arabia, the trees usually grow in saline (salty) soils, tolerating up to 15,000ppm of soluble salt, but will also tolerate basic soils. In the UK they are mainly planted near the sea in seaside towns as ornamental shrubs. It is also planted on sandy shores to act as a sand-stabiliser and as a windbreak. It seems to also have an established presence in the Greater London area, but perhaps that simply reflects the greater number of observers in that area. It doesn't grow north of Northumberland in the UK. It can self-seed, but that does not occur often.
The flowers are pinkish-white, small, up to 4mm across and have four petals, persisting when in fruit. The fruits are pinkish and shaped like a gourd. It flowers first in May, but there may be a second flowering in August in some years.
In the Middle East it has been used medicinally to treat rheumatism and diarrhoea. It can also treat liver damage due to such compounds as alcohol and other liver toxins.
Your Author admits he is puzzled by the number of petals reported by books and websites for Tamarisk. These sources say it has five petals, but the above photographs clearly show but four. In particular, he can find no photographs from other sources showing five petals! Can all written sources be wrong? Even Clive Stace writes that it has five petals. Or are the above photographs not of Tamarix? The Author finds that very hard to believe since all other photos on the web seem to show Tamarix with four petals. If anyone can shed light on this, please write in.
IsoRhamnetin (in trace amounts only) and one of its glycosides IsoRhamnetin-3-Glycoside are present in Tamarix, and are sometimes known as Tamarixetin and Tamarixin respectively on account of their being found in Tamarix. Tamarixetin is the 4'-methyl ether of Quercetin. Tamarix also contains Vitexin, which is also found in
Passion Flower and is the glycoside of the flavone Apigenin.