Hydroid

For the animals, see Hydrozoa.

Hydroid may refer to:

Marine biology

Hydroids are a life stage for most animals of class Hydrozoa, small predators related to jellyfish.

Botany

In mosses, hydroids form the innermost layer of the stem of long, colourless, thin walled cells of small diameter.The cells are dead and lack protoplasm.They function as water and nutrients conducting tissues analogous to tracheids. However, they lack any pitting or surface texture.[1]

Hydroids have been found in some Rhynie chert plants, including Aglaophyton, where they were initially mistaken for xylem vessels.

See also

References

  1. ^ Mishler, Brent D.; Steven P. Churchill (1984). "A Cladistic Approach to the Phylogeny of the "Bryophytes"". Brittonia (Brittonia, Vol. 36, No. 4) 36 (4): 406–24. doi:10.2307/2806602. ISSN 0007-196X. JSTOR 2806602.