VEXILLUM (Lat. dim. of velum, piece of cloth, sail, awning, or from vehere, vectum, to carry), the name for a small ensign consisting of a square cloth suspended from a cross-piece fixed to a spear. The vexillum was strictly the ensign of the maniple, as signum was of the cohort, but the term came to be used for all standards or ensigns other than the eagle (aquila) of the legion (see Flag). Caesar (B.G. ii. 20) uses the phrase vexillum proponere of the red flag hoisted over the general's tent as a signal for the march or battle. The standard-bearer of the maniple was styled vexillarius, but by the time of the Empire vexillum and vexillarius had gained a new significance. Tacitus uses these terms frequently both of a body of soldiers serving apart from the legion under a separate standard, and also with the addition of some word implying connexion with a legion of those soldiers who, after serving sixteen years with the legion, continued their service, under their own vexillum, with the legion. The term is also used for the scarf wrapped round a bishop's pastoral staff (q.v.). Modern science has adopted the word for the web or vein of a feather of a bird and of the large upper petal of flowers, such as the pea, whose corolla is shaped like a butterfly.