Spring into action with Plantlife: An introduction to grasses by Sarah Shuttleworth

Here are my notes from the fantastic presentation by Sarah Shuttleworth, hosted by Plantlife:

Why are grasses important?

The are one of the most diverse group of plants, ranging from annual to perennial. They spread from grasslands, to woodland, rocky shores and everything inbetween!

Grasses can regenerate after being eaten (of cut by lawn mowers), they also have the ability to store a lot of carbon. Up to 30% of carbon is actually stored in grasses. They also make up the majority of our diet.

Grass Anatomy

Stems, sheaths, ligules and auricles

The main part of the grass is called the culm (the stem) and is often uses to identify the species, such as if it's hairy or thick or has an interesting colour.

Node is a solid joint or region along the main stem and often thicker. They can be straight, or act as a 'knee' with the upper culm going off at an angle after the node. Sometimes the nodes can be much hairier than the culm.

The leaf blade can often be measured in aid of identification (particularly width). Do the leaves have ridges, or narrow parts, do the leaves curl in or are they hairy or shiny?

The leaf sheaf is the basal part of the grass leaf that encircles the stem. Can the culm be seen, or does the leaf sheaf cover the entire the culm (is it fused or partly fused or does it overlap?).

Ligule, a thin membranous outgrowth from the base of the blade that is present in most grasses. Sometimes the ligule is a ring of hairs instead of a membrane. Along with being either long or short, ligules can be smooth at the edge, rough, or fringed.

Auricles are an ear-like projection that appears from the leaf blade, where it meets the stem. 

Inflorescence is the group of flowers, with specific styles that help with ID. These include, panicle (Quaking grass), spike (Italian rye grass), raceme, and the spike-like panicle. 

Pedicel, a small stalk holding an individual flower within an inflorescence.

Spikelet, a flowering unit of two glumes and at least one floret.

Glume, two membranous bracts that surround a spikelet of a grass from the base. Sometimes stripy!

Floret is an individual flower of a grass spikelet.

Lemma is the lowermost of two chaff-like bracts that enclose the grass floret organs. It often bears a long bristle called an awn.

Palea is the interior chaff-like bract. Not often used for identification.

Awn, a hair-like / bristle-like projection. Awns can be on glumes, lemmas, or both.

Another fantastic presentation by Sarah, backed up with some fantastic videos, homemade models grass parts, and quizzes. If you get the chance to take part on one of Sarah's presentations, you'll come away with a lot of new knowledge!

Sarah Shuttleworth is a botanical specialist involved with the NPMS and botanical training across Plantlife. An experienced trainer with a talent for helping us all learn.