Crossword clues for archegonium
The Collaborative International Dictionary
Archegonium \Ar`che*go"ni*um\, n. [NL., fr. Gr. ? the first of a race.] (Bot.) The pistillidium or female organ in the higher cryptogamic plants, corresponding to the pistil in flowering plants.
Wiktionary
n. (context botany English) A multicellular reproductive structure that contains a large, non-motile gamete (egg cell), and within which an embryo will develop.
WordNet
n. a female sex organ occurring in mosses, ferns, and most gymnosperms
[also: archegonia (pl)]
Wikipedia
An archegonium (pl: archegonia), from the ancient Greek ἀρχή ("beginning") and γόνος ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete. The corresponding male organ is called the antheridium. The archegonium has a long neck canal or venter and a swollen base. Archegonia are typically located on the surface of the plant thallus, although in the hornworts they are embedded.
Usage examples of "archegonium".
It remains for long enclosed within the calyptra formed by the further development of the archegonial wall and surmounted by the neck of the archegonium.
When the archegonium opens by the separation of the cells at the tip, the disorganized canal-cells escape, leaving a narrow tubular passage leading down to the ovum.
Each antheridium or archegonium arises from a single cell, and while the mature structure is similar in the two groups, the development presents differences in liverworts and mosses.
Without entering into details it may be mentioned that in the mosses it proceeds both in the archegonium and antheridium by the segmentation of an apical cell, while this is not the case in the liverworts.
The sexual organs are developed in groups at the apices, the antheridial group usually terminating the main axis while the archegonia are borne on a lateral branch.
In the Acrogynous Jungermanniaceae the plant is throughout foliose, and the archegonia occupy the ends of the main shoot or of its branches.
In addition special involucres around the archegonia have arisen independently in several series.
The archegonia are protected by being sunk in depressions of the disk or by a special two-lipped involucre.
The small thallus bears the antheridia and archegonia, each of which is surrounded by a tubular involucre, on the upper surface of distinct individuals.
The archegonia are borne at the apex of the main stem or of a lateral branch.
The necks of the archegonia hardly project above the general surface of the thallus.
The sexual organs are developed in groups at the apices, the antheridial group usually terminating the main axis while the archegonia are borne on a lateral branch.
Their general similarity to the mature antheridia and archegonia of liverworts and the main difference in their development have been referred to.