Polypodium interjectum Shivas, 1961
Common names
- 🇬🇧 Intermediate Polypody
- 🇫🇷 Polypode intermédiaire
Taxonomy
- Kingdom: Plantae
- Clade: Tracheophytes
- Clade: Monilophytes
- Class: Polypodiopsida
- Subclass: Polypodiidae
- Order: Polypodiales
- Suborder: Polypodiineae
- Family: Polypodiaceae
- Subfamily: Polypodioideae
- Genus: Polypodium
- Species: Polypodium interjectum
Presence
Present.
Conservation status
- Red List (Metropolitan France): LC Least Concern
- Red List (Europe): LC Least Concern
Notes
Possible confusion with P. cambricum L., 1753, whose fronds are wider (width/length ratio is usually ≥ ½), becoming narrower abruptly at the tip with a long terminal segment, and whose pinnae are usually pointed.
Possible confusion with P. vulgare L., 1753, whose fronds are narrower (width/length ratio is usually ≤ ⅓), becoming narrower abruptly at the tip with a long terminal segment, and whose pinnae are usually rounded. P. vulgare sori are brown when mature, while those of P. interjectum are orange.
Due to the variability of characteristics between different individuals, differentiation of P. interjectum and P. vulgare on a macroscopic scale remains difficult and is often not reliable. Observing sporangia under a loupe or a microscope is the only reliable way to identify the species. P. interjectum has sporangia with a less visible, light brown annulus made of 7-9 cells, while P. vulgare has sporangia with a clearly visible, dark brown annulus made of 11-14 cells.
Individuals of P. interjectum with a higher count of indurated cells are not uncommon. In that case, the number of basal cells, as well as the color of the annulus should also be taken into consideration (Ivanova, 2006).
Allohexaploid (2n = 222).
Hybridizes with:
- P. cambricum L., 1753 to produce P. × shivasiae Rothm., 1962, P;
- P. vulgare L., 1753 to produce P. × mantoniae Rothm., 1962, P.
Photographs
Sources
Badré, F., & Deschatres, R. (1979). Les Ptéridophytes de la France : liste commentée des espèces (taxinomie, cytologie, écologie et répartition générale). Candollea, 34(2), 379-457. https://doi.org/10.5169/seals-880127
Christenhusz, M., Bento Elias, R., Dyer, R., Ivanenko, Y., Rouhan, G., Rumsey, F., & Väre, H. (2017). Polypodium interjectum (Europe assessment). The IUCN Red List of Threatened Species, 2017. https://www.iucnredlist.org/species/83650727/85447694
Ivanova, D. (2006). Polypodium interjectum and P. ×mantoniae (Polypodiaceae: Pteridophyta), new to the Bulgarian flora. Phytologia Balcanica, 12 (2), 191-202.
Prelli, R., & Boudrie, M. (2024). Les fougères et plantes alliées d’Europe (2nd ed., p. 420). Biotope.
Tison, J.M., & de Foucault, B. (2014). Flora Gallica : Flore de France (p. 23). Biotope.