AcanthaceaeAcanthus family

  - Leaves opposite, without stipules.
  - Stems swollen above the node.
  - Flowers with fused, bilaterally symmetric corolla.
  - Fruit a dry, explosive capsule.

Diagnosis: Herbs, shrubs, trees or climbers, leaves simple, without stipules, opposite, entire or uncommonly crenate, stem often swollen above the node, often with an interpetiolar ridge, often with cystoliths in the leaves.

Local distribution: Widespread.

Similar families
Amaranthaceae: stems swollen at nodes, not above, flowers small and radially symmetric.
Asteraceae: stems with pith, scratchy hairs.
Malpighiaceae: stipules, T-shaped hairs.
Verbenaceae: cuadrangular twigs, aromatic odor, nectar glands at leaf base.

Diversity: Total: 20 genera, 41 species. Trees: 2 genera, 2 species.

Comments: Most species have showy flowers; many are pollinated by hummingbirds.

Credits: Images and text copyright 2000-2007, William A. Haber,