Difference between Eupatorium Coelestinum and Ageratum

EUPATORIUM COELESTINUM vs AGERATUM: NOUN

Rhizomatous plant of central and southeastern United States and West Indies having large showy heads of clear blue flowers; sometimes placed in genus Eupatorium

Any of the genus Ageratum of tropical American herbs, annuals and perennials, from the sunflower family Asteraceae, tribe Eupatorieae; they are sometimes used in floral displays.
A genus of plants, natural order Compositæ, all American and chiefly tropical, nearly allied to Eupatorium.
Any of several other plants having flower clusters similar to those of ageratum.
Any of various tropical American plants of the genus Ageratum in the composite family, especially A. houstonianum, cultivated for their fluffy blue, purple, pink, or white flower heads.
Rhizomatous plant of central and southeastern United States and West Indies having large showy heads of clear blue flowers; sometimes placed in genus Eupatorium
Any plant of the genus Ageratum having opposite leaves and small heads of blue or white flowers

(proper noun) A genus of plants, one species of which (Ageratum Mexicanum) has lavender-blue flowers in dense clusters.

Homogamous, Genus ayapana, Eupatorium rugosum, Eupatorium aya pana, Eupatorin eupatorine, Dog fennel, Boneset, Ayapana triplinervis, Ayapana, Agueweed, Agrimony, Ageratina altissima, Conoclinium coelestinum, Mistflower, Ageratum

Clethra, Fritillaria, Scabiosa, Celosia, Sweet alyssum, Pasque flower, Zinnia, Rudbeckia, Eupatorium, Globe amaranth, Alyssum, Dusty miller, Mistflower, Eupatorium coelestinum, Conoclinium coelestinum

Liatris, Baptisia, Colchicum, Weigela, Clethra, Fritillaria, Scabiosa, Celosia, Sweet alyssum, Pasque flower, Rudbeckia, Eupatorium, Globe amaranth, Alyssum, Dusty miller

This hard to find, less hardy ageratum is a popular migration stop for many monarchs during their long journey to the mountains of Mexico.
Broad mites also infest many ornamentals, including African violet, ageratum, azalea, begonia, chrysanthemum, cyclamen, dahlia, gerbera, gloxinia, ivy, jasmine, impatiens, lantana, marigold, peperomia
Wax begonia, alyssum and ageratum also will benefit from an occasional snipping back.