Scheuchzeria palustris aka Rannoch Rush

Scheuchzeria palustris is a perennial plant known as Rannoch-rush or pod grass. It belongs to the family Scheuchzeriaceae, not the grass family. Despite its name and narrow leaves, it is not a grass. Its native range spans temperate parts of the Northern Hemisphere. The RHS also lists it as native to Britain and Ireland. It grows in bogs and swampy ground across this broad range. Kew describes its form as a rhizomatous geophyte or helophyte. These terms describe plants with underground growth or shoots in wet ground.

The plant has both rising and arching growth. Its green leaves are simple, narrow, and shaped like grass blades. They have smooth edges and no hairs on their surfaces. Each leaf joins the stem without a leaf stalk. The lower leaves can reach about 1.33 feet [0.41 metres] long. They are only about 0.01 feet [0.003 metres] wide. Leaves become smaller toward the upper part of the stem. Each leaf base wraps around the stem like a sheath. A thin membrane marks the point where sheath meets blade.

A small, open hole marks the tip of each leaf. This feature helps identify an otherwise easy-to-miss wetland plant. Its stems have no scent, according to NC State. The flowers are small rather than bold or showy. Each measures about 0.02 feet [0.006 metres] across. A raceme carries three to six flowers on short stalks. The flowers sit in an alternate pattern along the stem. Each flower has six tepals, rather than separate petals and sepals. Their colour ranges from purple-brown to a pale cream-white.

The fruit offers another useful clue to the plant's identity. Each capsule has three parts, with two seeds in each part. The capsules start green and turn yellow as they mature. Each measures about 0.02 feet [0.006 metres] in length. The seeds are dark brown and have an oval outline. They measure about 0.013 feet [0.004 metres] long. NC State's photographs show the capsules in early summer. Together, the three-part fruit and leaf-tip holes distinguish this modest plant.