About Polypodium interjectum Shivas
Polypodium interjectum Shivas is a medium-sized fern with a ladder-like arrangement of leaflets that forms an overall oval outline. Its frond is typically two to four times as long as it is wide, widening from both ends toward the middle or just below the middle. It has a truncated base that transitions abruptly to its stem, and mature basal leaflets often fold inward. This fern prefers mild growing conditions, in basic to slightly acidic soil, and grows in partial shade. When very young, the fertile sori located on the underside of the leaf are elliptic. Mature but still unopened sori are typically bright yellow. When sporangia are scraped from the underside of the leaf and viewed under a 200x or higher magnification lens, their annulus (a small backbone-like structure) has an average of 7 to 9 thick-walled cells, with a recorded range of 4 to 13. They also have 2 to 3 basal cells that are much wider than the annulus, and have no branched long paraphyses hairs (which would measure 0.5-1.4 mm if present). This species is distributed across most of Europe, far-western Russia, Turkey, and Iran.
