Ophioglossaceae
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Adder's-tongue family
Ophioglossaceae
ハナヤスリ科
One of the most primitive lineages among ferns. Leaves have a distinctive structure where a trophophore and a sporophore differentiate from a single common stalk. Includes Ophioglossum, Botrychium, and related genera, with multiple species native to Japan.
Key Characteristics
- ●Trophophore and sporophore differentiate from a single leaf (common stalk)
- ●Sporangia thick-walled (eusporangiate), lacking an annulus
- ●Prothallus subterranean with mycorrhizal association
- ●Some species have extremely high chromosome numbers (among the highest known)
Phylogenetic Position
Vascular plants > Polypodiophyta > Ophioglossopsida > Ophioglossales > Ophioglossaceae
Divergence Era
Devonian to Carboniferous (approx. 360 million years ago onward)
Representative Genera
ハナヤスリ属（Ophioglossum）ナツノハナワラビ属（Botrychium）
Related Evolution Events
- ・Retention of eusporangiate sporangia (a primitive characteristic)
- ・Extreme polyploidization (chromosome numbers reaching 2n=1440 in some species)
Plants in Adder's-tongue family on this site
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