- the rootlike base of a hydroid colony, by which it is attached to the substratum.
Origin of hydrorhiza
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for hydrorhiza
The colonies are cylindrical tubes about one quarter of an inch in height, rising from a creeping stem (hydrorhiza).The Sea-beach at Ebb-tide
Augusta Foote Arnold
In some cases, however, medusa-buds are formed on the hydrorhiza, as in Hydrocorallines.
The foot by which it is attached often sends out root-like processes—the hydrorhiza (c).
As a general rule polyp-buds are produced from the hydrorhiza and hydrocaulus, while medusa-buds are formed on the hydranth.