Sensitive Fern (Onoclea sensibilis)
Unlike many fern species, the sensitive fern does not form circular clumps, but rather spreads vegetatively with forking rhizomes to form irregularly-shaped colonies, which are occasionally quite dense.
(reproductive structure) that resemble beads at the top of the stalk. The fertile fronds are formed from mid-summer to October during normal years. The sterile fronds of the sensitive fern quickly turn brown and wither following the first exposure to frost, which is how this species gets its name. From late fall through the winter, the only evidence of its presence in a wetland is the persistent fertile fronds with their distinctive “beads-on-a-stick” appearance. C of C: 2
The separate fertile fronds are very different in this species, as the sporangia are arranged in a large number of hard, circular, brown sori
Dr. Bob Klips
This fern exhibits frond “dimorphism,” which means that it has both fertile (containing sporangia) and sterile fronds. The sterile frond is roughly triangular, usually about 12 to 24 inches long, with approximately 8 to 12 pairs of leaf segments (pinnae) arranged on opposite sides along the leaf stalk. The veins of these frond pinnae have a distinctive netted pattern. Larger plants can also have strong indentations at the margin of the pinnae.
Dr. Bob Klips
The sensitive fern is a common fern found throughout Ohio in wet places. This species can occur in dense colonies from full sun to partial shade, as long as the soil conditions remain moist for most of the growing season. It is frequently found within forested wetland habitat at the periphery of vernal pools.
Ferns
Fertile fronds
Sterile fronds 95