The Giant Spear Lily, endemic in South East Queensland, is sometimes seen in gardens.
It has a fleshy underground stem and a short above ground one.
There is a basal rosette of spirally arranged leaves.
Leaves, 2.5 to 3 m long by 20 cm wide, are sword-shaped and ribbed.
They have a long tubular tip that withers and becomes a dry brown thread.
A fully grown plant can be up to 4 m wide.
Each rosette produces a single, central flowering stalk up to 5 m high.
When the flowers are open the stalk bends over due to the weight.
The stalk below the flowers is covered in overlapping green leaves.
These are up to 30 cm long and their bases sheath the stem.
The upper 1 to 1.2 m of the stalk can hold over 300, slightly spread out flowers.
Under each flower is a large brownish-red bract.
The bisexual, brownish-red flowers are up to 10 cm across and 6 to 18 cm long.
There are 6 slightly fleshy tepals up to 10 or 12 cm long.
The inner surface is paler and whitish.
Their fused bases form a cup to hold nectar from the nectaries on the ovary.
The slightly spreading lobes are narrowly ovate with a blunt tip.
The 6 stamens, in 2 whorls of 3, do not extend beyond the tepals.
Their filaments are attached to the tepals for half their length.
The long, basifixed anthers, up to 3 cm long, open outwards via long slits.
The inferior ovary consists of fused carpels each with up to 50 ovules in 2 rows.
The placentation is axile.
There is a single, red apical style.
The fruit are tough, greenish to reddish, egg-shaped, loculicidal capsules up to 9 cm long.
The flat seeds, to 2 cm long, have a lateral wing.
After flowering, each plant produces vegetative buds in the leaf axils that form new rosettes.