\Vas"cu*lar\, a. [L. vasculum a small vessel, dim. of
vas vessel: cf. F. vasculaire. See {Vase}, and cf. Vessel.]
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 ph[ae]nogamous 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}, {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} (Zo["o]l.), 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.