Vitex agnus-castus (also called vitex, chaste tree / chastetree, chasteberry, Abraham's balm, lilac chastetree, or monk's pepper) is a plant native of the Mediterranean region. It is one of the few temperate-zone species of Vitex, which is on the whole a genus of tropical and subtropical flowering plants. Vitex is a cross-pollinating plant, but its self-pollination has been recorded.
Theophrastus mentioned the shrub several times, as ágnos (ἄγνος) in Enquiry into Plants. It has been long believed to be an anaphrodisiac – leading to its name as "chaste tree" – but its effectiveness for such action remains unproven. The shrub was utilized for religious rituals in ancient Greece and among the Philistines in Palestine as well as other countries in the Levant region. Its macaronic specific name agnus-castus repeats "chaste" in both Greek and Latin; the small tree was considered to be sacred to the virginal goddess Hestia/Vesta. The most common names are "chaste tree", "vitex", and "monk's pepper". It grows to a height of . It requires full sun, though tolerates partial shade, along with well-draining soil. Under ideal conditions, it is hardy to USDA Zone 6. In colder zones, the plant tends to die back to the ground, but as it flowers on new wood, flowering is not affected on vigorous growth in the following season. Cold and wet weather results in dieback and losses. The plant grows well on loamy, neutral to alkaline soil.
The fruits from one single tree can be harvested for more than 15 years. This indicates that the tree cannot be integrated in a usual crop rotation system. It is suggested to sow dissimilar plants such as monocots as its subsequent crop so that it might be easier to control the monk's pepper plant, the dicot. Because the fruits of monk's pepper tend to fall constantly and uncontrollably, the plant likely can germinate from seed.
Harvest
The flowering and ripening processes do not happen simultaneously, enabling harvesting of both fresh fruits and seeds over a long span of time. The fruits tend to fall from the plant as they ripen, getting lost in the soil. Thus, it has no optimal fixed harvest time. Consequently, to avoid yield loss, unripe fruits need to be harvested. This early harvesting has no effect on quality. The insect feeds on chaste tree by sucking up the fruit contents or puncturing them. Also, chaste tree is the only known host (especially in Israel) for Hyalesthes obsoletus. This cicada is the vector for black wood disease of grapevines. H. obsoletus prefers V. agnus-castus as a host to the grapevine. In this case, chaste trees can be used as a biological control agent by planting them around vineyards to trap the H. obsoletus.
V. agnus-castus was found not only to be an appropriate food source for the adult vectors, but also a reservoir of Candidatus phytoplasma solani (bacterial Phytoplasma species), the causal agent of the black wood disease in grapevines.
The pathogen-caused leaf spot disease can almost defoliate V. agnus castus. Furthermore, root rot can occur when soils are kept too moist.
Chemical compounds
Flavonoids (vitexin, casticin), iridoid glycoside (agnuside, aucubin), p-hydroxybenzoic acid, alkaloids, essential oils, fatty oils, diterpenoids and steroids have been identified in the chemical analysis of V. agnus-castus. They occur in the fruits and in the leaves.
Uses
thumb|Vitex agnus-castus ([[MHNT)]]
Culinary uses and folk medicine
The chaste tree, a local shrub known since the Lower Paleolithic, has been used by several ancient Mediterranean cultures as a spice.
Vitex has been used in folk medicine for its presumed reproductive health effects in women, but little high-quality clinical evidence supports its effectiveness. Although it is commonly recommended in Germany, V. agnus-castus should be avoided during pregnancy due to the possibility of complications.
Religious use
In ancient Greece, the chaste tree played a significant role in the female agricultural festival of Thesmophoria, dedicated to honoring the goddesses Demeter and Persephone in Greek cities. In Archaic Sparta, in the 8th–6th centuries BCE, it was incorporated into the cult of the local agriculture goddess, Artemis Orthia. The first century physician Dioscorides documented various synonyms for the lilac chaste tree. In the second century CE, Pausanias mentioned that the wooden image of Asclepius in Sparta was crafted from the chaste tree. Additionally, there is botanical and textual evidence supporting the significance of the chaste tree at the Heraion of Samos during the 6th–3rd centuries BCE. People taking dopamine-related medications or Parkinson's disease medications should avoid using chasteberry. Women on birth-control pills, hormone-replacement therapy, or having a hormone-sensitive condition, such as breast cancer, are advised not to use chasteberry.