Ophioglossum
| Ophioglossum | |
|---|---|
 | |
| Ophioglossum vulgatum | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pteridophyta |
| Class: | Psilotopsida |
| Order: | Ophioglossales |
| Family: | Ophioglossaceae |
| Genus: | Ophioglossum L. |
| Species | |
|
Some 25-30, including: | |
Ophioglossum, the adder's-tongue ferns, is a genus of about 25-30 species of ferns in the family Ophioglossaceae, of the order Ophioglossales. The name Ophioglossum comes from the Greek, and means "snake-tongue".[1]
Their cosmopolitan distribution is mainly in tropical and subtropical habitats.[1]
Description
Adders-tongues are so-called because the spore-bearing stalk is thought to resemble a snake's tongue. Each plant typically sends up a small, undivided leaf blade with netted venation, and the spore stalk forks from the leaf stalk, terminating in sporangia which are partially concealed within a structure with slitted sides.[1]
When the leaf blade is present, there is not always a spore stalk present, and the plants do not always send up a leaf, sometimes going for a year to a period of years living only under the soil, nourished by association with soil fungi.
The plant grows from a central, budding, fleshy structure with fleshy, radiating roots.
Taxonomy
Ophioglossum has the highest chromosome count of any known living organism, with 1,262 chromosomes.[2] In comparison, most species have far fewer chromosomes (e.g. humans have 46).[3]
Selected species
Species of Ophioglossum include:
- Ophioglossum austroasiaticum
- Ophioglossum azoricum
- Ophioglossum californicum
- Ophioglossum costatum
- Ophioglossum crotalophoroides
- Ophioglossum engelmannii
- Ophioglossum lusitanicum
- Ophioglossum nudicaule
- Ophioglossum pedunculosum
- Ophioglossum petiolatum
- Ophioglossum polyphyllum
- Ophioglossum pusillum
- Ophioglossum pycnosticum
- Ophioglossum reticulatum
- Ophioglossum tenerum
- Ophioglossum thermale
- Ophioglossum vulgatum
References
- 1 2 3 eFloras: Ophioglossum . accessed 2.14.2014.
- ↑ Gerardus J. H. Grubben (2004). Vegetables. PROTA. p. 404. ISBN 978-90-5782-147-9. Retrieved 10 March 2013.
- ↑ Biomysteries Blog: "Largest Chromosome number of Ophioglossum"
External links
- Flora of North America: Ophioglossum (Adder's-tongue)
- "The English Physician" by Culpeper: "Adder's Serpent" — description in 1814 herbalism book.
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