It is the principal genus of the natural order of Monocotyledous Potamogetonaceae, and contains plants with slender branched stems, and submerged and translucent, or floating and opaque,.
B, C, D, E, enlarged.) branched rootstock from which spring slender aerial shoots which are green, ribbed, and bear at each node a whorl of leaves reduced to a toothed sheath.
The polyp may then form a second bud, which becomes the starting point of a new system, the beginning, that is, of a new branch; and even a third bud, starting yet another system, may be produced from the same polyp. Hence the colonies of Calyptoblastea may be com plexly branched, and the bud ding may be biserial through out, uniserial throughout, or partly one, partly the other.
The radial canals may be simple or branched, primarily four, rarely six in number.
(c) Tentacles capitate, branched, wholly or in part; type of Cladocoryne.