I. In arch.
A. A little round moulding in the form of a ring, which encircles the upper part of a column, an astragal, Vitr. 3, 3.—
B. Lesbius, a sort of moulding carved to represent a string of pearls, a festoon, a stem with seeds of grain or olives, Vitr. 4, 6.—
II. A leguminous plant, Spanish tragacanth: Astragalus Baeticus, Linn.; Plin. 26, 8, 29, § 46.