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  1. Family: Acanthaceae Juss.
    1. Isoglossa Oerst.

      1. This genus is accepted, and is native to Asia-Tropical, Africa, New South Wales and Asia-Temperate..


    Flora Zambesiaca Acanthaceae (part 2) by Iain Darbyshire, Kaj Vollesen and Ensermu Kelbessa

    Annual or perennial herbs or shrubs, sometimes monocarpic and cyclically mass-flowering (plietesial); cystoliths present, linear, ± conspicuous.
    Stems (sub-)4- or 6-angular, often grooved between angles when young, at least in a dry state.
    Leaves evergreen or deciduous, opposite-decussate, pairs equal to anisophyllous, blade margin entire, undulate or shallowly crenate, lower leaves petiolate or subsessile, uppermost leaves and those subtending inflorescences often sessile with rounded or cordate base.
    Inflorescence terminal and/or axillary in upper leaf axils, rarely on older leafless branches; spiciform or laxly paniculate thyrses, branching dichasial and/or monochasial, cymules 1 to several-flowered; bract pairs ± equal, free, shape and size variable, sometimes foliaceous, sometimes rapidly reducing in size along main inflorescence axis; bracteoles as bracts or much-reduced.
    Calyx usually divided almost to base into 5 subequal lobes, often lengthening in fruit.
    Corolla bilabiate; indumentum variable but always glabrous towards base of tube externally; tube cylindrical, campanulate or inflated; upper lip ± hooded, apex 2-lobed, lobes often reflexed; lower lip oblong, elliptic or obovate, apex 3-lobed, median lobe broader than lateral pair, palate and throat often raised upwards with a longitudinal central furrow and herring-bone-like transverse ridging.
    Stamens 2; filaments attached at various heights within corolla tube, exserted or held at mouth; anthers bithecous, thecae strongly offset or at subequal height, parallel to highly oblique, upper theca larger than lower or pair subequal in size, basally muticous; staminodes absent.
    Disk shallowly cupular.
    Ovary (oblong-)ovoid, largely glabrous, bilocular, 2 ovules per locule; style filiform; stigma shortly bilobed.
    Capsule stipitate, placental base inelastic.
    Seeds 4 per capsule or fewer by abortion, held on retinacula, lenticular, compressed-ellipsoid or subdiscoid, with a hilar excavation, variously tuberculate, rugose or smooth.
    Genus of 50–70 species with a palaeotropical and subtropical distribution, most diverse in East Africa.



    Native to:

    Angola, Burundi, Cameroon, Cape Provinces, China South-Central, China Southeast, Comoros, East Himalaya, Ethiopia, Free State, Guinea, Gulf of Guinea Is., Jawa, Kenya, KwaZulu-Natal, Lesotho, Lesser Sunda Is., Madagascar, Malawi, Mozambique, New South Wales, Nigeria, Northern Provinces, Rwanda, Sierra Leone, Somalia, Sudan, Sulawesi, Swaziland, Tanzania, Thailand, Tibet, Uganda, Vietnam, Yemen, Zambia, Zaïre, Zimbabwe

    Accepted Species


    Other Data

    Isoglossa Oerst. appears in other Kew resources:


    First published in Vidensk. Meddel. Naturhist. Foren. Kjøbenhavn 1854: 155 (1855)


    Flora of West Tropical Africa

    • —F.T.A. 5: 227.

    Flora Zambesiaca

    • —Darbyshire in Kew Bull. 64: 401–427 (2009).
    • —Kiel et al. in Taxon 55: 683–694 (2006).
    • —Brummitt in Kew Bull. 40: 785–791 (1985).
    • —Hansen in Nordic J. Bot. 5: 5 (1985).
    • in Vidensk. Meddel. Dansk Naturhist. Foren. Kjobenhavn: 155 (1854), conserved name.


    Flora Zambesiaca
    Flora Zambesiaca

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at and
    © Copyright 2017 World Checklist of Selected Plant Families.

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at and
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.