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A solid mass of cellular tissue, consisting of one or more layers, usually in the form of a flat stratum or expansion, but sometimes erect or pendulous, and elongated and branching, and forming the substance of the thallogens.

Same as Internode.

The minute primary growth from the spore of ferns and other Pteridophyta, which bears the true sexual organs; the oöphoric generation of ferns, etc.

Not furnished with shields or beds for the spores, as the thallus of certain lichens.

of projection. -- Ground liverwort (Bot.), a flowerless plant with a broad flat forking thallus and the fruit raised on peduncled and radiated receptacles (Marchantia polymorpha). -- Ground mail, in Scotland, the fee paid for interment in a churchyard. -- Ground mass (Geol.), the fine-grained or glassy base of a ro…

America. -- Tree lungwort, a lichen (Sticta pulmonacea) growing on trees and rocks. The thallus is lacunose, and in appearance somewhat resembles the lungs, for diseases of which it was once thought a remedy.

s nonsexual, but produces spores in countless number. In ferns the oöphore is a minute prothallus; in mosses it is the leafy plant.

The surface of a leaf or of a flattened thallus.

n lichens, which is orbicular, flat, and sessile, and has a special rim not a part of the thallus.

Same as Prothallus.

A rounded apothecium having an elevated rim formed of the proper thallus, the fructification of certain lichens.

A patch of granular bodies on the surface of the thallus of lichens.

A layer or mass of cellular tissue, especially that part of the thallus of certain fungi which incloses the perithecia.

Same as Thallus.

Consisting of a thallus.

ich includes those flowerless plants, such as fungi, algæ, and lichens, that consist of a thallus only, composed of cellular tissue, or of a congeries of cells, or even of separate cells, and never show a distinction into root, stem, and leaf.

Resembling, or consisting of, thallus.

duce vegetatively or by means of asexual spores; in the higher forms the plant body is a thallus, which may be filamentous or may consist of plates of cells; it is commonly undifferentiated into stem, leaves, and roots, and shows no distinct tissue systems; the fronds of many algæ, however, are modified to serve many…