Vegetative key to the families

GRASSES. Herbs. Leaf bases modified to form an open sheath which encloses the stem; leaf blade with parallel venation and abruptly distinct from the sheath; LIGULE usually present at the top of the sheath (Fig 24) Poaceae
Spikelets unisexual, male and female markedly different and in different inflorescences; plants monoecious or dioecious
Female flowers not arranged in a globular head
Female flowers not surrounded by a bony utricle. Plants dioecious
Leaves crowded near the base of the plant, at least 1 m long. Inflorescence up to 1 m long, drooping Cortaderia
Inflorescence white or purplish, slightly exceeding the basal leaves. Leaf blades dull green, ± folded at the base, arching away from the stem and thus drooping well above the sheath. Large, tussocky plant up to 4 m high. Naturalized in wetter disturbed situations, particularly in urban bushland. Fl. summer–autumn. Pampas Grass Cortaderia selloana
Inflorescence always pinkish when young, fading to white, usually well exceeding the basal leaves. Leaf blades bright green, flat, drooping from immediately above the sheath. Only female plants found. Large, tussocky plant up to 4.5 m high. Naturalized in wetter disturbed situations, particularly in urban bushland. Fl. summer–autumn. Pink Pampas Grass Cortaderia jubata