Acanthaceae
There are 234 genera and about 2500 species in the Acanthaceae.
A genus well-known to temperate gardeners is Acanthus, Bear's breeches, perennials with big (up to 1 m (3') tall) leaves and equally large flower spikes.
More tropical genera would be Thunbergia[?] and Justicia[?].
Acanthaceae
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Scrophulariales
Family: Acanthaceae Genera
Acanthus L. -- bear's breech
Andrographis[?] Wallich ex Nees -- false waterwillow
Anisacanthus[?] Nees -- desert honeysuckle
Aphelandra[?] R. Br.
Asystasia[?] Blume
Barleria[?] L. -- Philippine violet
Barleriola[?] Oerst.
Blechum[?] P. Br.
Carlowrightia[?] Gray -- wrightwort
Dicliptera[?] Juss. -- foldwing
Dyschoriste[?] Nees -- snakeherb
Elytraria[?] Michx. -- scalystem
Eranthemum[?] L.
Graptophyllum[?] Nees
Hemigraphis[?] Nees
Henrya[?] Nees ex Benth.
Holographis[?] Nees
Hygrophila[?] R. Br. -- swampweed
Hypoestes[?] Soland. ex R. Br.
Justicia[?] L. -- justica, water-willow
Nelsonia[?] R. Br.
Odontonema[?] Nees -- toothedthread
Oplonia[?] Raf.
Pachystachys[?] Nees
Pseuderanthemum[?] Radlk.
Ruellia[?] L. -- wild petunia
Sanchezia[?] Ruiz & Pavón
Siphonoglossa[?] Oerst. -- tubetongue
Stenandrium[?] Nees -- shaggytuft
Teliostachya[?] Nees
Tetramerium[?] Nees
Thunbergia[?] Retz.
Yeatesia[?] Small -- bractspike
and about 200 more.
Ref: ITIS 34350 (http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=34350) 2002-09-07
For full list, see Kew (http://www.rbgkew.org.uk/cgi-bin/web.dbs/genlist.pl?ACANTHACEAE)