Shape: A colony forming fern with fronds that are broadly triangular, the fronds usually reclining giving an overall "formless" shape. Fronds: The sterile fronds are pale sea-green in color and turn yellow in autumn. They are easily killed by frost and thus comes the common name "sensitive". The sterile fronds are pinnatifid (the frond is once-divided with the divisions not reaching to the rachis [central stem]) to 1-pinnate (see photo for illustration). The leaves are quite broad with the central vein depressed and the smaller veins form a "netted" network which is unusual in the fern world. The rachis is smooth and the lower pinnae are usually the longest, giving the triangular shape. Spring fiddleheads are a pale red. Fertility: Spores are produced on separate fertile fronds which are green in the growing season and turn brown in the autumn. The sori (spore producing organs) are bead like and arranged toward the top of these separate fronds, which persist through winter and release their spores to the wind the following spring before new leaves form.

Habitat: The plant grows from a creeping rhizome in moist to wet soil, neutral to acidic and in sun or shade. They are fast growers and spreaders, almost invasive, (see photos below), thus needing frequent division if you wish to control them. In the garden they mix well with Siberian iris, hosta, or turtlehead. The fertile fronds work well in dried flower arrangements or provide winter interest in the landscape. Sensitive Fern grows in hardiness zones 2 to 10. The genus name is from the Greek and refers to a closed vessel, referring to the sori enclosed in the rolled margins of the fertile pinnae. The species name refers to the plants sensitivity to frost.