Related Searches
on Ask.com
ferns - 4 dictionary results
fern
[furn] 
–noun
| any seedless, nonflowering vascular plant of the class Filicinae, of tropical to temperate regions, characterized by true roots produced from a rhizome, triangular fronds that uncoil upward and have a branching vein system, and reproduction by spores contained in sporangia that appear as brown dots on the underside of the fronds. |
Origin:
bef. 900; ME ferne, OE fearn; c. G Farn fern, Skt parná feather
bef. 900; ME ferne, OE fearn; c. G Farn fern, Skt parná feather
Related forms:
fernless, adjective
fernlike, adjective
Fern
[furn] –noun
| a female given name. |
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source
|
Link To ferns
| fern (fûrn) n. Any of numerous flowerless, seedless vascular plants having roots, stems, and fronds and reproducing by spores. [Middle English, from Old English fearn; see per-2 in Indo-European roots.] fern'y adj. |
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
| fern (fûrn) Pronunciation Key
Any of numerous seedless vascular plants belonging to the phylum Pterophyta that reproduce by means of spores and usually have feathery fronds divided into many leaflets. Most species of ferns are homosporous (producing only one kind of spore). The haploid spore grows into a small, usually flat gametophyte known as a prothallus, which is undifferentiated into roots, stems, and leaves. The green prothallus anchors itself with hairlike extensions known as rhizoids and bears both archegonia (organs producing female gametes) and antheridia (organs producing male gametes). The male gametes require the presence of water to swim to the female gametes and fertilize the eggs. Normally only one embryo is produced, and it then grows out of the gametophyte plant as a diploid sporophyte plant that has roots, stems, and leaves and conducts photosynthesis, while the smaller gametophyte withers away. The leaves of these sporophytes eventually produce sporangia (in some species occurring in clusters known as sori). Under dry conditions, the sori burst releasing hundreds of thousands or millions of spores. Ferns were abundant in the Carboniferous period and exist today in about 11,000 species, about three-quarters of which live in tropical climates. |
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2009, Dictionary.com, LLC. All rights reserved.
