Development from spore to mature perithecia takes about two weeks.
Spores are ejected from peritheciasingly or in groups of 2 to 4 spores, although groups as large as 12 spores have been found.
Fraxini, which may be distinguished from the ascigerous perithecia with which they are associated by their smaller size and flask-like shape.
Except in the perithecia rupturing irregularly, and not dehiscing by a pore, some of the genera in this group differ little in structure from the Sphæriacei.
The perithecia are either orbicular or elongated, and the hymenium soon becomes exposed.
Each of the tubes is then divided by transverse septa into two or three distinct cells, and in this manner the cellular walls of the perithecia come into existence.
In Chætomium, the peritheciabristle with rigid, dark-coloured hairs, and the sporidia are coloured.
Sometimes the perithecia are solitary or scattered, and sometimes gregarious, whilst in other instances they are closely aggregated and immersed in a stroma of variable size and form.
The walls of the perithecia, rather more carbonaceous than membranaceous, are reticulated, reminding one of the conceptacles of Erysiphe, to which the perithecia bear considerable resemblance.
The perithecia contain pear-shaped asci, which spring from the base and enclose a definite number of sporidia.
And in Sphæriacei, although the substance is variable, the hymenium is never exposed, being enclosed in perithecia with a distinct opening at the apex, through which the mature spores escape.
Also that the perithecia themselves are not perforated at the apex.
Externally these perithecia are usually furnished with long, spreading, intertwined, or branching appendages, sometimes beautifully branched or hooked at their tips.
The cytological details of development of the perithecia are not well known; most of them appear to develop their ascogenous hyphae in an apogamous way without any connexion with an ascogonium.
The perithecia were long, cylindrical, and were arranged in a circle or were contiguous, near the summit of the stroma.
In the following plants we find no perithecia in the ripe specimens, hence of course they will in time be considered a genus.
Perithecia linear, contiguous, near the apex of the plant.
In reality, I think it is a better Camillea, the perithecia arranged the same way, not permanent, but broken up at an early stage.
Phylacia might be held distinct from Camillea on the ground of the powdery mass and the early disappearance of the perithecia and ascus walls.
The original, by Ehrenberg, represents them as hollow bodies, with the perithecia imbedded in the walls.
The walls of the perithecia are carbonous, and confluent with the crust.
They have a solid carbonous interior with the perithecia imbedded near the surface.
Perithecia arranged in a central bundle, with permanent, carbonous walls (Fig.
Perithecia carbonous, forming several stratose layers, imbedded in the stroma in the depressions.
The peritheciaare generally imbedded in the outer portion of the stroma, the mouths opening through the carbonous crust.
From Montagne's sectional figure, the peritheciaare arranged in the same manner, and the two plants are surely cogeneric and, I believe, identical.
The perithecia are arranged in a circle neat the apex of the stroma.
Perithecia (the hollow narrow-mouthed cases which contain the spores) gregarious, with a cottony stroma in which they are more or less immersed.
In this Fungus the black bottle-like perithecia (fig.
The spores are ejected from the apothecia and perithecia as in the fungi by forcible ejaculation from the asci.
The term sporules he applies to the spores of imperfect fungi, where they are enclosed in perithecia (microscopic cups or cells), such as the Sphaeropsidea.
The term conidia he uses to designate the spores of imperfect fungi without perithecia or asci, such as the Hyphomyceteae and the Melanconieae.
The perithecia are produced on the mycelial mats beneath the loose and sometimes cracked bark of diseased oaks.
The sexual form is recognized by the appearance of microscopic, black, short-beaked fruiting structures or perithecia that are filled with sticky ascospores.
Perithecia erect, in a polished and colored sac Oomyces.
An ordinary hand glass will show how it bears perithecia in all its parts.
In fructification a stalk rises from the body of the insect or larva and in the enlarged extremity of this the perithecia are grouped.
Perithecia carbonaceous or membranaceous, sometimes confluent with the stroma, pierced at the apex, and mostly papillate; hymenium diffluent.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "perithecia" in a variety of sentences. We hope that you will now be able to make sentences using this word.
