Production Resources

Identifying the parts of a wheat head

Wheat

Identifying the structure and function of wheat head parts is important for making management decisions, describing insect and diseases issues, communicating with others in the industry, and reviewing agronomic material. Agronomic information is more accessible than ever, but the level of detail and terminology differ among sources. This document provides background information on the plant parts of a wheat head and their function.

Table 1. Summary of wheat head parts and their purpose in the plant

Part (alternative name)	Role
Head (spike, ear, inflorescence)	The head contains the plant’s reproductive organs and ultimately wheat grains.
Anthers (flowers)	Anthers are yellow, filamentous organs that are part of the male reproductive system. They produce and release pollen. During anthesis (flowering) they can be found protruding from florets.
Rachis	The main stem of the wheat head. Central point where spikelets are attached.
Peduncle (upper stem)	The peduncle is the stem that is directly below and supports the head.
Spikelet	Spikelets are the main flowering unit of the wheat head and are made up of multiple florets. Two glumes are found at the base of each spikelet, which enclose and protect the florets.
Floret	Florets are individual flower units within spikelets. Each floret includes both the male and female reproductive organs needed for grain development. Generally, each spikelet has 1-5 florets. Florets are enclosed and protected by two bracts, the palea and lemma.
Glumes	The glumes are the outermost bracts that enclose and protect the spikelet.
Palea	The palea is the inner, upper bract that encloses the flower in the floret.
Lemma	The lemma is the outer, lower bract that encloses the flower in the floret.
Awns	Long and bristle-like growths that originate from the lemma and point vertically into the air.

Below are pictures and diagrams that depict the plant organs above.

Figure 1. Wheat head parts during flowering. Picture depicts wheat head, awns, anthers, peduncle, rachis and spikelet. Image courtesy of University of Wisconsin (used with permission).

Figure 2. An example of a wheat head spikelet, glumes and pedicel. Image courtesy of Grain Farmers of Ontario Visual Guide to Winter Wheat Staging.

Figure 3. An example of an opened wheat head spikelet that shows the palea, lemma and florets. Image courtesy of Grain Farmers of Ontario Visual Guide to Winter Wheat Staging.