prothallium

American  

[proh-thal-ee-uhm] / proʊˈθæl i əm /

noun

plural

prothallia

1. Botany. the gametophyte of ferns and related plants.

2. the analogous rudimentary gametophyte of seed-bearing plants.

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Other Word Forms

• prothallial adjective
• prothallic adjective
• prothalline adjective
• prothalloid adjective

Etymology

Origin of prothallium

1855–60; < New Latin < Greek pro- pro- ² + thallíon, diminutive of thallós young shoot; see -ium

Example Sentences

In the full-grown ovule the macrospore, which in the seed plants is generally known as the “embryo sac,” is completely filled with the prothallium or “endosperm.”

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton

The pollen cell forms two or three divisions, which are either permanent or soon absorbed; this, as before stated, is the rudimentary male prothallium.

From Scientific American Supplement, No. 531, March 6, 1886 by Various

But the asexual generation derived from the oospore only for a short while remains in connection with the prothallium, which, of course, answers to the leafy portion of the moss.

From Scientific American Supplement, No. 531, March 6, 1886 by Various

In the upper part of the prothallium several large archegonia are formed in much the same way as in the pteridophytes.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton

The spore produces the small green prothallium by cell-division in the usual way, and this completes the cycle of fern life.

From Scientific American Supplement, No. 531, March 6, 1886 by Various