The structure of grass-flowers has been already described, and the reader should refer back to page 19. The inflorescence is a spike, the spikelets arranged in two rows, with their edges to the stem, which is channelled. There is only one outer glume, which is strongly ribbed, and shorter than the spikelet. The flowering glumes number from six to ten, or more.

This is one of the grasses that send forth leafy runners, which root and occupy surrounding ground. It is one of the most valuable to the farmer, on account of it early ripening, and its usefulness either for permanent pasture or for cropping. With good management as many as four crops may be obtained in one year. It grows in all waste places, and flowers in May.

The Darnel (L. temulentum) is its only native congener; an annual. It is similar to L. perenne, but produces no runners. Its presence among wheat is dreaded, as when ground up into flour it is believed to produce headache, vertigo, and other symptoms of poisoning. Darnel is the Tares of the New Testament, and is one of the very few grasses that are deleterious.

Upright Brome (Bromus erectus) is a perennial of strong growth, with stout creeping rootstock, sending up smooth and rigid stems 2 or 3 feet in height. The narrow leaves have their edges rolled inwards. The inflorescence is a lax panicle; the spikelets purplish in tint. The two empty glumes are unequal, and contain from five to eight flowering glumes, with awns, and hairy all over. There are seven other British species in the genus.