Acanthaceae
Our editors will review what you’ve submitted and determine whether to revise the article.
Acanthaceae, one of 24 families in the mint order (Lamiales) of flowering plants, containing approximately 220 genera and nearly 4,000 species distributed predominantly in tropical and subtropical regions of the world. The greater part of the Acanthaceae family are herbs orshrubs, butvines andtrees occur as well. The range ofhabitats extends frommarshes andestuaries to extremely dry situations, but most of these plants are found in damp tropical forests.
Adiverse family, Acanthaceae has few universal characteristics among its members. Most have simpleleaves arranged in opposite pairs, withcystoliths (enlarged cells containing crystals of calcium carbonate) in streaks or protuberances in the vegetative parts. The bisexual flowers are frequently bilaterally symmetrical and are usually enclosed by leaflikebracts, often coloured and large. Sepals and petals number five or four each and are often fused into tubular structures. There are usually two or fourstamens that extend beyond the mouth of theflower, often with one to three staminodes (sterile stamens). Thepistil is superior (i.e., positioned above the attachment point of the other flower parts) and generally consists of two fused carpels (ovule-bearing segments) enclosing two locules (chambers), each of which has two to manyovules in two rows along the central axis of the ovary. The fruits are often explodingcapsules containingseeds borne on hooks on the placenta.
The group is mainly ofhorticultural interest and includes such ornamentals asbear’s-breech (Acanthus mollis),clockvine (Thunbergia),shrimp plant (Justicia brandegeana), andcaricature-plant (Graptophyllum pictum). The largest genera includeJusticia (600 species; nowcomprising former segregate genera such asJacobinia andBeloperone),Reullia (355),Stobilanthes (350),Barleria (300),Aphelandra (170),Staurogyne (140),Dicliptera (150),Blepharis (130),Lepidagathis (100),Hygrophila (100),Thunbergia (90), andDyschoriste (80). The small genusAvicennia contains at least eight species of ecologically important mangroves.
