Nephrolepis – 15cm
fishbone fern, herringbone fern, sword fern
Native of tropical and subtropical regions of the world including Australia (north from the north coast of NSW).
It is found in rainforests or open forests.
This is a semi-evergreen fern that is usually terrestrial (growing on the ground). The rhizomes (underground horizontal stems) are covered with brown scales. The stolons (horizontal above-ground stems) are slender and wiry, also with some scales. Sometimes there are globe-shaped tubers on the stolons. This plant forms dense clumps.
Fronds (the leaf of a fern) may be upright or hanging downward and up to 75cm long. The pinnae (the green leafy parts along the leaf) are in 2 rows on either side of the rachis (stem of the leaf), they are slightly regular to toothed, older leaves have spores on the underside. Pinnae are crowded along the rachis.
The sori (cluster of spores) are a row of dots on the lower surface near the margin and have persistent pale green indusium (tissue covering the sorus). Sometimes there are raised dots on the upper surface near the margins of the pinnae where the spores are pushing into the leaf from below.
Fishbone fern spreads by stolon and by wind-blown spores.
This plant may be dugout. The roots usually are not deep but form quite dense mats. If it is in dense matted clumps remove the central part of the roots from where the leaves are growing (the crown) with a knife.