Lewis & Short

plumbāgo, ĭnis, f. [plumbum].

  1. I. A species of lead ore, black-lead, plumbago, also called molybdaena, Plin. 34, 18, 50, § 168.
    1. B. Transf., a leaden color in gems, Plin. 37, 5, 18, § 68.
  2. II. A plant, also called molybdaena, leadwort, fleawort, Plin. 25, 13, 97, § 155.