1. Family: Acanthaceae Juss.
    1. Hygrophila R.Br.

      1. This genus is accepted, and its native range is Tropics & Subtropics.

    [FTEA]

    Acanthaceae (part 2), Kaj Vollesen. Flora of Tropical East Africa. 2008

    Habit
    Perennial herb with short erect or ascending stems from branched rhizome; stems up to 10 cm long, hirsute to tomentose Annual (? short-lived perennial) herb; stems creeping and rooting, ascending apically, spongy and inflated basally, up to 40 cm long, crisped-pubescent Perennial herb with short creeping stems and ascending to erect inflorescences; stems to 15 cm long, uniformly pubescent with broad glossy hairs
    Leaves
    Leaves sharply reflexed; lamina narrowly elliptic, largest 5–8 × 1–1.5 cm, apex acute, base subhastate, whitish hirsute-strigose above, below on veins and margins and subglabrous on lamina Leaves narrowly elliptic, largest ± 5 × 0.8 cm, apex acute, on both sides pubescent with broad glossy hairs Leaves lanceolate to narrowly ovate-elliptic, largest ± 2.5 × 0.5 cm, apex rounded, base cuneate, densely strigose-pubescent with broad glossy hairs
    Stamens
    Only 2 stamens developed with no trace of staminodes; filaments ± 5 mm long, with long thin hairs; anthers ± 1 mm long
    Seeds
    Seed ± 0.5 mm long.
    Inflorescences
    Inflorescence racemoid, interrupted at base, denser upwards; axes densely pubescent with broad glossy hairs; floral leaves like vegetative; flowers solitary or paired at lower nodes; bracteoles to 1 cm long; pedicels to 1 mm long Inflorescence spiciform, interrupted basally and confluent towards apex, up to 20 cm long; axes with indumentum as stems or denser and with long capitate glands intermixed towards apex; cymes up to 8-flowered (fewer upwards), sessile or basal with peduncle up to 1 mm long; bracts lanceolate, up to 1.5 cm long; pedicels ± 1 mm long; bracteoles linear-lanceolate, ± 9 mm long
    Filaments
    Filaments minutely puberulous, 2–3 (upper) and 4–5 (lower) mm long; anthers ± 1.5 mm long
    Note
    Known only from this collection. Most closely related to H. pobeguinii from which it differs in the densely hairy stem, inflorescence and calyx, smaller leaves and larger corolla. Clearly related to H. richardsiae with which it shares the perennial habit and absence of spines in the inflorescences. It differs in the much smaller flowers. From spineless forms of H. schulli it differs in the perennial habit. It differs from both in not having the two dorsal sepals fused almost to the apex and in the relatively long linear corolla tube. Known only from this collection. With a superficial resemblance to H. cataractae, but differing in a number of important characters. It has only two fertile stamens with no staminodes, no orange spots and no long stiff hairs on the lower corolla-lip. The indumentum is also considerably denser than in H. cataractae.
    Flowers
    Flowers in dense sessile fascicles merging into heads in the upper part of the stem, without spines; floral leaves and bracts foliaceous, gradually smaller upwards, hard and ± bony in basal part, inner lanceolate, to 1.5 cm long, hirsute-strigose
    Calyx
    Calyx hirsute-strigose apically and long-ciliate, 11–13 mm long; lobes all strongly ribbed, all fused for ± 8 mm at base, ventral and lateral narrowly triangular, dorsal 2–3 mm longer and oblanceolate-spathulate Calyx uniformly strigose-pubescent, 8–10 mm long of which the basal fused part ± 3 mm; ventral and lateral lobes linear, dorsal lanceolate and ± 2 mm longer than the rest Calyx puberulous with broad glossy hairs and with capitate glands, ± 11 mm long of which the fused basal part ± 1 mm; lobes linear-lanceolate, dorsal slightly longer than rest
    Corolla
    Corolla bright blue, “herring-bones” inconspicuous, crisped-puberulous, no capitate glands, ± 27 mm long of which linear tube ± 12 mm and expanded tube plus limb ± 15 mm; upper lip obovate, lobes 8–9 mm long, rounded; lower lip with scattered long curly hairs, broadly obovate, lobes 7–8 mm long, rounded or retuse (central); some flowers with 4 subequal stamens, others with 2 fertile stamens (dorsal) and two staminodes without anthers; filaments glabrous, ± 4 mm long; anthers ± 3.5 mm long Corolla mauve, without (?) markings, no “herring bones”, puberulous, no capitate glands, ± 15 mm long of which the linear tube ± 5 mm and expanded tube plus limb ± 10 mm; upper lip narrowly ovate, lobes rounded; lower lip obovate, with stiff tapering hairs, lobes 2–3 mm long, rounded Corolla white with pale pink lower lip, without discernible “herring-bones”, sparsely finely puberulous, ± 12 mm long of which the tube ± 8 mm long; upper lip ovate, with two short rounded lobes; lower lip broadly obovate, without orange spots and without long stiff hairs, lobes ± 2 mm long, rounded
    Fruits
    Capsule and seed not seen. Capsule and seed not seen Capsule 7–8 mm long, finely puberulous near apex, with 20–24 seeds per locule
    Ecology
    Short valley bottom grassland on sandy-loamy soil; ± 1700 m Montane grassland; ± 1800 m Small swampy area in Brachystegia woodland on grey sandy soil; ± 300 m
    Distribution
    Range: Not known elsewhere Range: Not known elsewhere Flora districts: T4 Range: Not known elsewhere Flora districts: T4 Flora districts: T6

    Images

    Distribution

    Native to:

    Alabama, Andaman Is., Angola, Argentina Northeast, Argentina Northwest, Assam, Bangladesh, Belize, Benin, Bolivia, Botswana, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Burkina, Burundi, Cambodia, Cameroon, Caprivi Strip, Central African Repu, Chad, Colombia, Congo, Cuba, Dominican Republic, East Himalaya, Ecuador, El Salvador, Equatorial Guinea, Eritrea, Ethiopia, French Guiana, Gambia, Ghana, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, India, Ivory Coast, Jamaica, Kenya, Korea, KwaZulu-Natal, Laos, Lesser Sunda Is., Liberia, Malawi, Maldives, Mali, Mauritania, Mexico Gulf, Mexico Southeast, Mexico Southwest, Mozambique, Myanmar, Namibia, Nepal, Nicaragua, Nicobar Is., Niger, Nigeria, Northern Provinces, Pakistan, Panamá, Paraguay, Peru, Philippines, Puerto Rico, Rwanda, Senegal, Sierra Leone, Sri Lanka, Sudan, Suriname, Swaziland, Tanzania, Thailand, Togo, Trinidad-Tobago, Uganda, Uruguay, Venezuela, Vietnam, West Himalaya, Zambia, Zaïre, Zimbabwe

    Introduced into:

    Society Is., South Carolina

    Hygrophila R.Br. appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    s.coll. [Cat. no. s.n.], Bangladesh Cardanthera K001132507

    First published in Prodr. Fl. Nov. Holland.: 479 (1810)

    Literature

    Flora of West Tropical Africa
    • Benoist in Bull. Soc. Bot. Fr. 60: 330 (1913).
    • —F.T.A. 5: 30

    Sources

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    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 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