Vas·cu·lar a.
 1. Biol. (a) Consisting of, or containing, vessels as an essential part of a structure; full of vessels; specifically Bot., pertaining to, or containing, special ducts, or tubes, for the circulation of sap. (b) Operating by means of, or made up of an arrangement of, vessels; as, the vascular system in animals, including the arteries, veins, capillaries, lacteals, etc. (c) Of or pertaining to the vessels of animal and vegetable bodies; as, the vascular functions.
 2. Bot. Of or pertaining to the higher division of plants, that is, the phaenogamous plants, all of which are vascular, in distinction from the cryptogams, which to a large extent are cellular only.
 Vascular plants Bot., plants composed in part of vascular tissue, as all flowering plants and the higher cryptogamous plants, or those of the class Pteridophyta.  Cf. Cellular plants, under Cellular.
 Vascular system Bot., the body of associated ducts and woody fiber; the fibrovascular part of plants.
 Vascular tissue Bot., vegetable tissue composed partly of ducts, or sap tubes.
 Water vascular system Zool., a system of vessels in annelids, nemerteans, and many other invertebrates, containing a circulating fluid analogous to blood, but not of the same composition. In annelids the fluid which they contain is usually red, but in some it is green, in others yellow, or whitish.

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 Cel·lu·lar a.
 1. Consisting of, or containing, cells; of or pertaining to a cell or cells.
 Cellular plants, Cellular cryptogams Bot., those flowerless plants which have no ducts or fiber in their tissue, as mosses, fungi, lichens, and algæ.
 Cellular theory, or Cell theory Biol., a theory, according to which the essential element of every tissue, either vegetable or animal, is a cell; the whole series of cells having been formed from the development of the germ cell and by differentiation converted into tissues and organs which, both in plants and animals, are to be considered as a mass of minute cells communicating with each other.
 Cellular tissue. (a) Anat. See conjunctive tissue under Conjunctive. (b) Bot. Tissue composed entirely of parenchyma, and having no woody fiber or ducts.

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