POACEAE Grasses Where are the Grass Flowers Grass

POACEAE: Grasses

Where are the Grass Flowers?

Grass Flower “Normal” Flower Grass Flower

Grass Flowers: Lodicules • Scale-Like Structures (2 -3) at Base of Stamens • Interpreted as Rudimentary Perianth Parts

Grass Floret = Flower Enclosed in Two Flower Bracts (Lemma (Usually on outside), Palea (Usually on inside))

Grass Florets with Mature Flowers

Grass Florets with Mature Fruit (= Caryopsis = Grain)

Grass Floret: Lemma • Usually facing outwards • Often green to brown • Variable number of nerves

Grass Floret: Lemma (Often with Awns = Bristles)

Grass Floret: Palea • Usually facing inwards • Usually translucent • Generally, two nerves

Grass Spikelet = Two Glumes + Floret(s)

Grass Spikelet: Glumes (= Bracts of the Spikelet)

Grass Spikelet: Glumes (Often with Awns)

Spikelets with One Floret

Spikelets with Multiple Florets

Spikelets: Rachilla (= Stalk within Spikelet to which Florets are Attached)

Spikelets: Rachilla (= Stalk within Spikelet to which Florets are Attached)

Grass Spikelet: Callus (Hard Projection at base of Floret or Spikelet)

Grass Spikelet: Callus (Hard Projection at base of Floret or Spikelet)

Grass Spikelet: Pedicel (Stalk of the Spikelet)

Grass (Poaceae) vs. Sedge (Cyperaceae) vs. Rush (Juncaceae) Flowers

Essential Grass Floral Terminology • • • Floret Lemma Awn Palea Lodicule Callus • Spikelet • Glumes • Glume Awn • Rachilla • Pedicel