adder’s-tongue fern

fern genus

Also known as: Ophioglossum

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July 23, 2026

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The adder's-tongue fern, belonging to the genus Ophioglossum, is a type of primitive fern within the family Ophioglossaceae. These ferns are characterized by a unique frond structure, divided into a sterile blade and a fertile spike containing spore-producing structures called sporangia. Most species produce only one frond per season.12

The genus Ophioglossum is notable for having the highest number of chromosomes known in any organism, with one species, O. reticulatum, possessing 1,440 chromosomes. The smallest terrestrial fern, O. malviae, also belongs to this genus. These ferns are found in tropical and temperate regions and are of interest to botanists due to their primitive characteristics and unusual chromosomal makeup.2

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Ophioglossaceae
The genus Ophioglossum (adder’s-tongue ferns), with 46 tropical and temperate species, has sporangia in two rows near the tip of a usually unbranched narrow fertile spike. The group is of interest because its members have the highest number of chromosomes of any organisms known to science; O. reticulatum…
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The genus Ophioglossum (adder’s-tongue ferns), with 46 tropical and temperate species, has sporangia in two rows near the tip of a usually unbranched narrow fertile spike. The group is of interest because its members have the highest number of chromosomes of any organisms known to science; O. reticulatum…
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plant reproductive system
Ferns
In primitive ferns, such as Ophioglossum and Botrychium, the spores are borne upon a specialized axis, the fertile spike. The sporangia of such primitive ferns are massive, with several layers of cellular walls, and produce an indefinite but large number of spores. In most other ferns, the sporangia are smaller…
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In primitive ferns, such as Ophioglossum and Botrychium, the spores are borne upon a specialized axis, the fertile spike. The sporangia of such primitive ferns are massive, with several layers of cellular walls, and produce an indefinite but large number of spores. In most other ferns, the sporangia are smaller…
Read More