Caste tree, latin name: vitex agnus castus，a species of Verbenaceae family of vitex plant.This flowering shrubs have palmately compound leaf which are narrowly lanceolate blade, located to very short or nearly without pedicals;Calyxes are bell-like with purple colour，flowering is during June to August，clusters of those purple flowers have soothing effect on nervous system, they stand out under the palmate leaves. 

Flowers would wither and fall，pale brown spherical fruits are produced afterwards, and they will turn into dark brown colour when ripen.Those unripened pepper-like sized fruits are harvested with flower spikes,and processed with steam distillation or hydrosol extraction.

There are 250 species of vitex plants spread overtroplical areas and temperate zone. The European species mainly planted in mediterranean area. 

Caste tree grows in mediterranean area and this herbaeous plant has been used since ancient times and has a medicinal history of at least 2000 years. The ancient Greeks began to eat the fruit of the spike, and they believe that the spike can inhibit sexual demand, so those wifes can appease their emotions because of their husbands are on battle fields perennially far from home so anthoer name of the Virgin Raspberry come from here. In Italy, the monastery is also planted in the courtyard of this flower, called the monk pepper.

Essential oils extracted from leaves or fruits have different chemical compositions. The essential oils extracted from the leaves are relatively low in monoterpene, but have the same healing effects that are worth affirming. 

As people always say,caste tree has medinical effect on balancing the function of human body,this plant grows along side the waterary areas bathing in the sun,the Yin-Yang growing environment boost the engergy in this plant and  popurlarly pursued by people!