Traditional Chinese medicine uses it against asthma and acute bronchitis attacks. It is a hot spicy product that releases the cold biao wind. Its main property is that it allows to do the sweating.
Verbena officinalis, the common vervain or common verbena, is a perennial herb native to Europe. It grows up to a metre/yard high, with an upright habitus. The lobed leaves are toothed, the delicate spikes hold mauve flowers.