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A kelp, for example, may have its thallus divided into three regions. The parts of a kelp thallus include the holdfast (anchor), stipe (supports the blades) and the blades (for photosynthesis). [2] The thallus of a fungus is usually called a mycelium. The term thallus is also commonly used to refer to the vegetative body of a lichen.
A byssoid lichen has a wispy, cottony or teased wool appearance due to the loosely woven hyphae in its thallus. [13] It has no outer cortex. [14] Lichens with this growth type can be split into two types. In one type, the thallus is dominated by fungal hyphae, with a photobiont – typically a coccoid green alga – sprinkled throughout. In the ...
The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. [1] The erect portion of the thallus is dichotomous or subpinnately branched, flattened and with a distinct midrib. Gas-filled pneumatocysts (air-vesicles) are present in pairs in some species, one on either side of the midrib.
Lichen growth forms are used to group lichens by "vegetative" thallus types, and forms of "non-vegetative" reproductive parts. Some lichen thalli have the aspect of leaves (foliose lichens); others cover the substrate like a crust (crustose lichens) ( illustration, right ), others such as the genus Ramalina adopt shrubby forms (fruticose ...
The body of a lichens that does not contain reproductive parts of the fungus is called the thallus. The thallus is different from those of either the fungus or alga growing separately. The fungus surrounds the algal cells, often enclosing them within complex fungal tissues unique to lichen associations.
The thallus has little to no tissue differentiation, being composed of thin, compactly arranged uniform parenchymatous cells. Anthoceros species are host to species of Nostoc , a symbiotic relationship in which Nostoc provides nitrogen to its host through cells known as heterocysts , and which are able to carry out photosynthesis . [ 3 ]
In lichens it refers to the region of the thallus that is free of algae. The prothallus develops from a germinating spore. It is a short-lived and inconspicuous heart-shaped structure typically 2–5 millimeters wide, with a number of rhizoids (root-like hairs) growing underneath, and the sex organs: archegonium (female) and antheridium (male ...
Ocellularia vizcayensis has a white thallus that is areolate, meaning it has a loosely structured surface divided into irregular areas.The thallus is covered with a loose cortex, and both the layer containing the photobiont (photosynthetic partner) and the medulla (the inner layer) have large clusters of calcium oxalate crystals.