Identification of Cereal Crops

Cereal crops can usually be identified after harvest by the remains of the fruiting heads (‘ears’) lying around as part of the stubble-field trash; in Spring these remains become sparser and more difficult to find and in set-aside fields they have usually disappeared by the second winter. The alternative is to identify the crop from seedlings arising from the spilt seed. SBAL surveyors are recommended to settle for ‘Unknown cereal’ if neither infructescences nor seedlings are present, and information cannot be obtained from the farmer .

Identification by discarded fruiting heads

The flowering and fruiting heads of oats are open panicles, with the spikelets borne on long pedicels.

The flowering and fruiting heads of barley, wheat, rye and triticale are dense spikes with sessile spikelets. Barley (Hordeum) has spikelets in groups of 3 at each node. This is easier to detect in Six-rowed Barley than in Two-rowed Barley as in the former all three spikelets are fertile and have a long awn, whereas in Two-rowed Barley the outer spikelets are much smaller, awnless and sterile. Wheat (Triticum), rye (Secale) and their hybrid triticale (X Triticosecale) have a single spikelet at each node (like Lolium perenne). If the spikelets lack a long awn they can be identified with confidence as wheat. However, awned cultivars of wheat are sometimes grown and even Stace’s New Flora of the British Isles (1997) admits that they are easily confused at first glance with rye; to complicate matters, the hybrid triticale is sometimes grown. In the relatively rare event of finding a crop with spikelets which are borne singly at the node and awned, one has to resort to the technical differences set out by Stace, or ask the farmer.

Wheat has several florets per spikelet (3-7 or more), with the uppermost 2 or more florets reduced and sterile. The glumes are broad, 5-7 veined and truncate.
Rye has 2(-3) florets per spikelet, and all are fertile. The glumes are very narrow, 1-veined and acute.
Triticale differs from wheat in having obtuse glumes. The glumes are broader than those of rye and unlike that cereal, the uppermost florets of the spikelet are sterile.

Identification by seedlings

The seedlings of the three common crop species can be identified from the leaf auricles, using the following mnemonic:

Barley bare (auricles present, glabrous)
Wheat whiskered (auricles present, often hairy)
Oats absent (auricles absent)

Oats and barley have glabrous leaf sheaths, the sheaths of wheat have a dense covering of short hairs whereas those of rye have conspicuous long hairs amongst the short.

C.D.Preston

 

There is a sheet of fine illustrations showing the important taxonomic features, kindly drawn by Graham Easy and prepared by Gill Stevens. It will appear in a new browser window which needs to be closed to return to the main site, and should print out on a single A4 sheet.