Hyssopus officinalis or hyssop is a herbaceous plant of the genus Hyssopus (belonging to the Lamiaceae, or mint family), native to Southern Europe, the Middle East, and the region surrounding the Caspian Sea. Due to its properties as an antiseptic, cough reliever, and expectorant, it is commonly used as a medicinal plant. Hyssop is a brightly coloured shrub or subshrub that ranges from 30 to 60 cm (12 to 24 in) in height. The stem is woody at the base, from which grow a number of straight branches. Its leaves are lanceolate, dark green in colour, and from 2 to 2.5 cm (0.79 to 0.98 in) long. During the summer, the plant produces bunches of pink, blue, or, more rarely, white fragrant flowers. These give rise to small oblong achenes. A plant called hyssop has been in use since classical antiquity. Its name is a direct adaptation from the Greek ὕσσωπος (hyssopos). The Hebrew word אזוב (ezov, esov, or esob) and the Greek word ὕσσωπος probably share a common (but unknown) origin. The name hyssop appears as a translation of ezov in some translations of the Bible, notably in verse 7 of Psalm 51: 'Thou shalt purge me with hyssop, and I shall be clean' (King James Bible), but researchers have suggested that the Biblical accounts refer not to the plant currently known as hyssop but rather to one of a number of different herbs, including Origanum syriacum (Syrian oregano, commonly referred to as 'bible hyssop'). I Kings iv. 33 mentions that 'ezov' was a small plant. It was burned with the Red Heifer (Num. xix. 6) and used for purification of lepers (Lev. xiv. 4, 6, 49, 51; comp. Num. xix. 18; Ps. li. 9), and at Passover it was used to sprinkle the blood of the sacrificial lamb on the doorposts (Ex. xii. 22). A sponge attached to a hyssop branch was used to give Jesus on the cross a drink of vinegar. Hyssop was also used for purgation (religious purification) in Egypt, where, according to Chaeremon the Stoic, the priests used to eat it with bread in order to purify this type of food and make it suitable for their austere diet. The species as a whole is resistant to drought, and tolerant of chalky, sandy soils. It thrives in full sun and warm climates. Cultivars include 'Blue Flower'.