from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A sperm-producing organ occurring in seedless plants, fungi, and algae.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An organ producing male gametes called antherozoids, found in lower plants.
from the GNU version of the Collaborative International Dictionary of English
- n. The male reproductive apparatus in the lower plants, consisting of a cell or other cavity in which spermatozoids are produced; -- called also spermary.
from The Century Dictionary and Cyclopedia
- n. In botany, the organ in cryptogamic plants which answers to the anther in the phanerogamic series. It assumes various forms and positions in the different groups. Also called antherid.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the male sex organ of spore-producing plants; produces antherozoids; equivalent to the anther in flowers
In Bryophytes, the antheridium is the male sex organ, which produces sperm.
It is called an "antheridium," and within are produced, by internal division, numerous excessively small spermatozoids.
The male plant has no definite stem, and consists of a single concave leaf protecting the antheridium.
C. Longitudinal section of antheridium; st, stalk; w, wall.
_J_, a male prothallium, × 50. _an. _ an antheridium.
In both cases the prothallium is small, and often scarcely protrudes beyond the spore, and may be reduced to a single archegonium or antheridium (Fig. 71, _B_, _C_) with only one or two cells representing the vegetative cells of the prothallium (_v_).
If a ripe antheridium is crushed in a drop of water, after lying a few minutes the spermatozoids will escape through small openings in the side of the cells.
The antheridium undergoes no further change, but the archicarp soon divides into two cells, -- a small basal one and a larger upper cell.
In many species special zoöspores are formed, smaller than the ordinary ones, that attach themselves to the filaments bearing the female reproductive organ (oögonium), and grow into small plants bearing the male organ (antheridium), (Fig. 16, _B_).
The other branch (antheridium) grows up in close contact with the archicarp, and like it is shut off by a partition from its filament.