Oenothera. Oenothera biennis L. Tree Primrose. Evening Primrose. Onagre, Fr. Nachtkerze, Gr. (Fam. Onagraceae.) —The fleshy root of this plant, before the introduction of the potato, was used as a table vegetable. Many years ago R. E. Griffith commended very highly a strong decoction of the plant frequently applied to eruptive skin diseases. More recently the drug has been commended in whooping cough and spasmodic asthma, and the ointment has been used in prurigo and other cutaneous affections of infants, and as an application to ulcers. Dose, of fluidextract, from a half to one fluidrachm (1.8-3.75 mils). The ointment may be made by incorporating four ounces of the fluidextract in a pound of vaseline or lard.