The Collaborative International Dictionary
Discoid flower
Discoid \Dis"coid\, a. [Gr. ? quoit-shaped, ? a round plate, quoit + e'i^dos form, shape: cf. F. disco["i]de. See Disk.] Having the form of a disk, as those univalve shells which have the whorls in one plane, so as to form a disk, as the pearly nautilus.
Discoid flower (Bot.), a compound flower, consisting of tubular florets only, as a tansy, lacking the rays which are seen in the daisy and sunflower.