A young woman, richly robed in blue, stands on a silver-gray ground, holding a martyr’s palm in one hand and a green branch in the other; the latter recalls the branch held by the courtier who personifies the month of April in the Belles Heures (Timothy B. Husband, The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry, 2008).
In his Etymologiae, the seventh-century encyclopedist Saint Isidore of Seville explains that when the sun is in this sign the heat-scorched earth is barren; hence the constellation is named Virgo, or the Virgin. Another encyclopedic work, the thirteenth-century Breviari d’amor, concurs in this explanation, adding that it is the dryness of the season that keeps the earth from bearing fruit. However, this sterility is belied by the personification of the sign in medieval Books of Hours, where the young virgin represented often holds green fronds or branches, with or without fruit, and may also be shown with wheat sheaves. The palm frond, an emblem of victory and an attribute of virgin-martyrs—as well as a symbol of the Virgin Mary herself—was given to Virgo. Wheat, too, was identified with the Virgin, and these Christian elements were incorporated into the calendar tradition inherited from antiquity (Teresa Pérez-Higuera, Medieval Calendars, 1998).