1. Family: Acanthaceae Juss.
    1. Genus: Barleria L.
      1. Barleria grootbergensis I.Darbysh. & E.A.Tripp

        This species is accepted, and its native range is Namibia.

    [KBu]

    Darbyshire, I., Tripp, E.A. & Dexter, K.G. Kew Bull (2012) 67: 759. https://doi.org/10.1007/s12225-012-9393-1

    Habit
    Shrub to 100 cm tall
    Stem
    Mature stems densely white-velutinous, the trichomes minute, declinate, interspersed with occasional longer appressed trichomes; uppermost internodes patent glandular-pubescent
    Leaves
    Leaves ovate or lanceolate, 3.8 – 5.3 × 1.4 – 2 cm, base cuneate, apex acute or attenuate, lateral veins 4 pairs; leaf buds densely white-strigulose but mature leaves soon glabrescent except for sparse strigose trichomes along the margin, midrib and lateral veins beneath, some trichomes ‘anvil-shaped’ (i.e. biramous with one long arm and one short arm), uppermost leaf pairs also glandular-pubescent; cystoliths conspicuous on both surfaces without magnification, sessile glands visible on upper surfaces with magnification; petiole to 6 mm long
    Inflorescences
    Inflorescences short dense terminal spikes 3.5 – 5 cm long, of a series of subsessile single-flowered opposite cymules; bracts, bracteoles and calyces pale yellow-green, densely glandular-pubescent throughout; bracts caducous in fruit, elliptic (excluding larger basal leaf-like pair), 18 – 22 × 5.5 – 8 mm, apex acute or subattenuate; bracteoles narrowly elliptic or oblanceolate-elliptic, 15.5 – 20 × 2.5 – 5 mm, held erect and ± equalling the calyx, apex acute
    Calyx
    Calyx 4-lobed; abaxial lobe elliptic, 17 – 18.5 × 7 – 8 mm, base cuneate, apex shallowly notched for up to 2.5 mm, surface with 5 – 7 prominent subparallel veins; posticous lobe elliptic, 17.5 – 20 × 6.5 – 7 mm, apex acute or shortly attenuate; lateral lobes lanceolate, ± 11 × 2 mm, margin hyaline
    Corolla
    Corolla pale purple with whitish throat and tube, 48 – 52 mm long, with sparse mixed glandular and eglandular trichomes on the lateral lobes externally; tube 25 – 28 mm long, unexpanded basal portion of the tube ± 3 – 4 mm in diam., gradually expanded above attachment point of stamens to ± 6 – 6.5 mm in diam- at the mouth; lobes in ‘4 + 1’ arrangement, abaxial lobe offset by 9 mm from the remaining lobes, broadly obovate, 17.5 × 14.5 mm; lateral lobes elliptic-obovate, 17 × 13 mm; adaxial lobes elliptic-obovate, 18.5 × 9.5 mm
    Stamens
    Stamens attached 7 mm from base of corolla tube; filaments 31 mm long, minutely pubescent at the base; anthers 4 mm long; lateral staminodes to 1.5 mm long, flattened and triangular, minutely pubescent, antherodes absent; adaxial staminode minute
    Pollen
    Pollen trizonocolporate, globose in equatorial view, 3-lobed in polar view, with coarse deep reticulation of the interapertural and polar exine
    Ovary
    Ovary 4 mm long, distal portion densely mixed glandular- and eglandular-puberulous; style 35 – 43 mm long, glabrous; stigma linear, 2.5 – 2.8 mm long, curved
    Fruits
    Capsule 13 – 16 × 6 – 7 mm, including prominent beak 4 – 6 mm long, beaked portion covered with short glandular and/or eglandular trichomes, fertile portion glabrous; seeds c- 5 – 6 × 4 – 5 [very few seen], covered in non-mucilaginous, crisped hygroscopic trichomes.
    Distribution
    NW Namibia; known only from the type locality.
    Ecology
    Growing on rocky slopes including loose scree close to the road; 1400 m alt.
    Conservation
    This species is currently known from a single locality, where it is very localised. Less than 15 plants were seen in the vicinity; however we should note that population size was not assessed in an exhaustive manner. Based on current data, it is apparently highly restricted in its range, having not been collected previously despite being found along one of the main roads between the popular Skeleton Coast and Etosha Pan. However, much of the mountainous region to the north and south of the road over the Grootberg Pass is inaccessible by vehicle and has probably never been botanised. Satellite imagery available on Google Earth (http://www.google.co.uk/intl/en_uk/earth/index.html) suggests that there are extensive areas of potentially suitable habitat for Barleria grootbergensis in this region. Furthermore, there appears to be little threat to the only known population given that the area is generally not heavily travelled. The only habitation in the immediate vicinity is that of a small eco-lodge, which is owned and operated by the Grootberg Conservancy and thus unlikely to significantly impact the population in a negative manner. Whilst this species must currently be considered Data Deficient (DD) (IUCN 2001) pending further survey work, it may ultimately prove to be unthreatened.
    Note
    The minute white-velutinous indumentum on the mature stems, the densely glandular inflorescence indumentum and the general facies of the flowers place this species close to Barleria lancifolia T. Anderson, a species that is widespread and common in Namibia. B. grootbergensis is, however, easily separable from B. lancifolia by its dense terminal spikes with the calyces largely hidden within the ± erect yellow-green bracts and bracteoles, the latter subequal in length to the calyces. In B. lancifolia, the cymules are more distantly spaced along the axis, at least in the lower portion of the inflorescence where the bracts are foliaceous. The bracts in the upper portion of the inflorescence in B. lancifolia are greatly reduced and proportionally narrowed (though remaining green) and are more spreading than in B. grootbergensis. The calyces of B. lancifolia are also always clearly exposed (see Fig. 4). The bracteoles in B. lancifolia are generally shorter than the calyx and ≤ 15 mm in length in single-flowered cymules (the lower cymules of the inflorescence are often 3-flowered). Finally, the glandular trichomes of the inflorescence in B. grootbergensis are somewhat longer and more dense (particularly on the bracts) than those of B. lancifolia. The combination of prominently beaked, two-seeded capsules (Fig. 2D), three staminodes lacking antherodes, linear stigmas, absence of spines and non-stellate indumenta place Barleria grootbergensis within section Somalia of Barleria with confidence (Balkwill & Balkwill1997; Darbyshire2009).

    Distribution

    Native to:

    Namibia

    Barleria grootbergensis I.Darbysh. & E.A.Tripp appears in other Kew resources:

    First published in Kew Bull. 67: 760 (2012)

    Literature

    Kew Bulletin
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    • Meyer, P. G. (1968). 130. Acanthaceae. In: H. Merxmüller (ed.) Prodromuseiner Flora von Südwestafrika. J. Cramer, Lehre.Google Scholar
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    Sources

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Bulletin
    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0