Aster
Collier's New Encyclopedia (1921)
a genus of plants, the type of the order asteraceæ, or composites. It is so called because the expanded flowers resemble stars. There is but one British species, the A. tripolium, sea starwort, or Michaelmas daisy. In the United States these asters grow wild in the meadows and on the prairies. They grow to beautiful forms under cultivation. The popular name aster is applied to some species not of this genus. Thus the China aster is callistephus chinensis, and the Cape aster agathæa amelloides. ASTERACEÆ (as-ter-as'e-i), formerly, an order, the fourth of five arranged under the alliance compositæ, or asterales, the others being calyceraceæ, mutisiaceæ, cichoraceæ, and cynaraceæ. These, excluding cynaraceæ, constitute the compositæ proper. The term asteraceæ in this sense is called also corymbiferæ, and comprehends the larger portion of the modern tubulifloræ. Now, it is a vast order, comprising the whole of the compositæ proper. It includes plants like the daisy, the thistle, the dandelion, and others, possessing what, to a superficial observer, appears like a calyx, but is in reality an involucre, surrounding a receptacle on which are situated not, as might at first sight appear, numerous petals, but many florets. They are believed to constitute about one-tenth of the flowering plants. They are everywhere diffused, but in different proportions in different countries; thus they constitute one-seventh of the flowering plants of France, and half those of tropical America. The order is divided into three suborders: (1) tubulifloræ; (2) labiatiflora ; and (3) ligulifloræ. All are bitter. For more spe specific information regarding their qualities see the sub -orders and some of the genera. ASTEROIDS. See PLANETOIDS.
What Has Changed in the Last Century
Collier's in 1921 could say American asters "grow wild in the meadows and on the prairies" as members of the genus Aster; DNA work in the 1990s and 2000s broke that up, and almost all North American species were moved to other genera, chiefly Symphyotrichum (the New York and New England asters and garden Michaelmas daisies), along with Eurybia, Doellingeria and others. Aster itself is now treated as an essentially Eurasian genus, and even the sole "British species" cited here, A. tripolium, has been reassigned as Tripolium pannonicum. The old division of Compositae into tubuliflorae, labiatiflorae and liguliflorae has likewise given way to a molecular scheme of subfamilies such as Asteroideae and Cichorioideae. The one figure that has held up well is the estimate that the family makes up roughly a tenth of flowering plants: modern counts put Asteraceae near 25,000-33,000 species, among the largest of all plant families.
Written for this edition, 2026.