General description:- Herbs or shrubs.

Leaves:- Simple, opposite, without stipules (exstipulate).

Flowers:- With one plane of sym­metry (zygomorphic). Inflorescences spike-like.
Bracts often conspicuous, coloured. Calyx 4-lobed, 2-lipped, or bell-shaped
(campanulate), 5-fid. Corolla petals united (sympetalous), zygomorphic, with a short
tube; limb 2-lipped with the upper lip subentire and the lower 3-petalled (3-fid), or 1-
lipped with the upper lip absent. Stamens 2 or 4. Ovary superior, 2-locular, with
axile placentae; style single, unequally 2-lobed.

Fruit:- Capsule, when ripe splits into the cells along the midrib or dorsal suture.
(loculicidal), capsule with a hardened (indurated) seed stalk (funicle), which has a
hook-like process on the stalk that helps in dispersal i.e. eject the seeds
(jaculators)

ACANTHUS

General description:- Robust perennial herbs or small shrubs.

Stems:- Simple, circular in cross section (terete), erect.

Leaves:- Mostly basal, lobed, the lobes extending from about a quarter to half-way
towards the centre or almost so, (pinnatifid or pinnatisect).

Flowers:- In dense, terminal, cylindrical spikes. Bracts large, Spiny to toothed
(spinose-dentate); bracteoles entire, lance-shaped to linear. Calyx 4-lobed; upper
and lower lobes large, the lateral small. Corolla 1-lipped (upper lip absent), 3-lobed;
tube short. Stamens 4, included; anthers 1-celled, joined (connate) in pairs.

Fruit:- A capsule.

Key features:-
1) Basal leaves pinnatifid to pinnatisect.
2) Corolla 1-lipped.

ACANTHACEAE