Bot. and Herb. [mod.L. agēratum, ad. (by Linnæus) cl. L. agēraton, a. Gr. ἀγήρᾰτον name of a plant in Dioscorides and Pliny, prop. neuter of ἀγήρατος not growing old, f. ἀ priv. + γήρας, -ατος old age. Formerly also in the Gr. form.]
† 1. Herb. Some kind of everlasting flower, known to the ancients. Obs.
1567. Maplet, Greene Forest, 31. Ageraton is like Origan or Marigolde.
1601. Holland, Pliny (1634), II. 271. Ageraton, it is an herb of the Ferula kind the flowers resemble buttons or brooches of gold.
1706. Phillips, Ageraton, an Herb calld Everlasting; Mothwort, Cotton-weed, or Maudlin.
1753. Chambers, Cycl. Supp., Ageratum bears a near resemblance to the costmary.
1879. Syd. Soc. Lex., Ageraton was probably the Achillea ageratum.
2. A genus of plants (N.O. Compositæ, Div. Eupatoriæ), of which one species (A. Mexicanum), with lavender-blue flowers in dense clustered capitules, is a favorite garden annual.
1866. W. Thompson, in Treas. Bot., 30. The Cœlestina ageratoides, a half-hardy perennial with blue ageratum-like flowerheads, much employed in bedding, must not be confounded with the true Ageratums.