Thallophyta


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Thallophyta

[thə′läf·əd·ə]
(botany)
The equivalent name for Thallobionta.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Thallophyta

 

one of the two subkingdoms of the plant world; it comprises bacteria, actinomycetes, myxomycetes, fungi, algae, and lichens. The body of thallophytes, the thallus, is not divided into a root, stem, and leaf; multicellular reproductive organs are absent.

Thallophytes include procaryotes, cells lacking a true nucleus (bacteria, actinomycetes, blue-green algae), and eucaryotes, cells with a true nucleus (the remaining members of the subkingdom). They are unicellular (mostly microscopic) or multicellular (up to 40 m long) and heterotrophic (most bacteria, actinomycetes, myxomycetes, fungi) or autotrophic (some bacteria, algae [including those living in lichens]). The more highly organized thallophytes have leaflike organs and a conducting system similar to the phloem of higher plants; the zygote develops in a multicellular embryo on a gametophyte (some brown algae).

Fossil remains of several thallophytes—bacteria and unicellular algae—have been found in Archean and Proterozoan deposits about 3 billion years old.

REFERENCES

Kursanov, L. I., and N. A. Komarnitskii. Kurs nizshikh rastenii, 3rd ed. Moscow, 1945.
Malyi praktikum po nizshim rasteniiam. Moscow, 1967.

IU. E. PETROV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.