1.4 Grasses

Grasses

Inflorescence Spike Palea

Spikelet

Lemma

Glume

Ligule

Sheath

Figure 1.4

Grass parts

Auricle: ear-shaped appendage of a grass leaf where it meets the stem Awn: bristle-like extension at the tip or back of lemma or glume Dorsally compressed: spikelets that are flattened from front to back Floret: an individual flower within a grass spikelet Glume: paired bracts at the base of grass florets’ Laterally compressed: spikelets that are flattened from the sides Lemma: lower of two bracts of a grass floret, often partially surrounding the palea Ligule: in Poaceae species, an appendage at the junction of the inner leaf with the leaf sheath; can be membranous or ciliate (with hairs) Palea: the upper of two bracts of a grass floret, often partially enclosed by lemma Sheath: the base of the grass leaf that surrounds the stem; can be open or closed; sides of closed sheaths touch, and open sheaths have a gap between sides (Poaceae and Potamogetonaceae species) Spike: a long, unbranched inflorescence with sessile flowers, maturing from the bottom upward Spikelet: basic unit of a grass flower usually consisting of two glumes and one or more florets