Aster
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. i ASTEROIDS 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 specific more spe specific information regarding their qualities see the sub -orders and some of the genera.
ASTEROIDS. See PLANETOIDS.