Plant of the month 01/2023: Scleria sphacelata

Photos by Russell Cumming, text by Julia Hazel

Thanks to Nanette for identifying this interesting sedge during a recent walk around the top of Mount Stuart.

Scleria sphacelata (Cyperaceae) is a dioecious species, unlike most other Scleria species, so it bears distinct male and female flowers on separate plants.

Flowers of a female Scleria sphacelata plant are shown above. See flowers of a male plant on this page courtesy of Steve & Alison1.

Scleria sphacelata and various other plants with sharp-edged narrow leaves, are commonly called “razor grass”. But for botanists, sedges are NOT grasses!

For a simple way to distinguish the Family of “grass-like” plants, look at the stem (culm) and remember this rhyme:

Sedges have edges,
Rushes are round,
Grasses have nodes from the top to the ground.

Sedges are in the Cyperaceae family. Their stems are often triangular and you can see or feel “edges” on the stems. The stems are solid with no nodes.

Rushes are in the Juncaceae family. They have round (cylindrical) stems which are solid with no nodes.

Grasses are in the Poaceae family. Their stems are round and hollow with solid nodes (swollen joints).

There are exceptions to these simple differences and it’s best to use a botanical key for details.