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This genus is accepted, and its native range is Tropics & Subtropics to N. America.


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

Morphology General Habit
Erect shrubby perennial herb, 1 m tall; young stems sparsely puberulous and with scattered glands in two bands below nodes Perennial or shrubby herbs or shrubs; cystoliths conspicuous
Morphology Reproductive morphology Flowers
Flowers solitary in leaf axils towards apex of stem; pedicels 0–1 mm long; bracteoles narrowly ovate, up to 2.2 × 0.5 cm, decurrent into a petiole which is longer than the lamina Flowers solitary or paired in leaf axils or in variously branched cymes or panicles; bracts persistent, leaf-like; bracteoles persistent (rarely caducous), usually large and leafy
Morphology Reproductive morphology Flowers Calyx
Calyx 16–20 mm long, divided to 1–2 mm from base; puberulous with glandular and non-glandular hairs; lobes linear Calyx 5-lobed, deeply divided into 5 subequal lobes or 2–3 lobes fused higher up; lobes usually with distinct dorsal keel, dorsal usually slightly longer than the rest
Morphology Reproductive morphology Flowers Corolla
Corolla open during the day, blue (? mauve); tube ± 5 cm long of which the basal cylindric part ± 3.5 cm and the throat ± 1.5 cm long; lobes ± 1 × 1 cm, broadly ovate with rounded apex Corolla hairy on the outside, contorted in bud, subactinomorphic; basal cylindric part of tube short to long, throat short to long, usually much widened upwards; lobes 5, subequal, spreading
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens included in throat, slightly didynamous; filaments fused for ± 3 mm at base, free parts ± 6 and 8 mm long, longer with scattered spreading hairs near base; anthers ± 5.5 mm long Stamens 4, subequal to didynamous, inserted near base of throat, exserted or included in throat; free part of filaments fused at base, below insertion forming two ridges running to base of tube; anthers 2-thecous, thecae oblong, rounded at base, without spurs, connective with small curved appendage at apex
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary not seen. Ovary with 3 to many ovules per locule.
Lowland semi-evergreen forest; ± 175 m
Known only from this collection. Superficially close to R. amabilis from which it differs in the cuneate leaf-base, broader bracteoles, shorter corolla tube, sessile flowers and blue corolla. These two last characters indicate that its real affinity is possibly more with the R. patula-group. From the species in this group it differs in the large anthers, large capsule and large seeds. The native East African species all belong to Subgen. Dipteracanthus (Nees) C.B.Clarke which is characterised by having a clavate capsule with sterile basal part.
Morphology Leaves
Leaves opposite, entire to crenate Leaves with petiole 1–3.5 cm long, densely puberulous; lamina ovate, largest 9 × 4.2 cm, apex gradually narrowed into an elongated acute tip, base cuneate, unequal-sided, sparsely puberulous and with scattered glands
Morphology Reproductive morphology Flowers Gynoecium Style
Style filiform, hairy throughout or glabrous towards apex.
Morphology Reproductive morphology Flowers Gynoecium Stigma
Stigma with dorsal lobe reduced to a small tooth (rarely well developed), ventral lobe large, flattened to spoon-shaped with wavy margin Ventral stigma lobe ± 3 mm long
Morphology Reproductive morphology Fruits
Capsule cylindric to clavate, valves eventually splitting lengthwise from bottom up along dorsal suture, with 4 to over 20 seeds; retinaculae strongly hooked Capsule strongly clavate, with scattered capitate glands in upper 1/4, ± 27 mm long, 8-seeded
Morphology Reproductive morphology Seeds
Seed discoid, faces glabrous or with discoid hairs, rim strongly raised and with dense hygroscopic hairs Seed orbicular, dark brown, ± 6 × 5.5 mm.
Range: Not known elsewhere Flora districts: T6 Range: About 250 species widely distributed in all tropical regions, most numerous in South America.


M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008]

Morphology General Habit
Herbs or shrubs
Morphology Leaves
Leaves entire
Morphology Reproductive morphology Inflorescences
Flowers single or few together in axillary cymes; bracts and bracteoles leaf-like
Morphology Reproductive morphology Flowers
Calyx 5-lobed; lobes equal. Corolla with a short to long cylindrical tube, widened in the upper portion; lobes 5, subequal. Stamens 4; anthers 2-celled with cells parallel to each other
Morphology Reproductive morphology Fruits
Capsule many-seeded
Morphology Reproductive morphology Seeds
Seeds smooth, flat, orbicular, with mucilaginous hairs especially along the margin.
Genus of some 350 species, mainly in the tropics.

Native to:

Alabama, Aldabra, Andaman Is., Angola, Argentina Northeast, Argentina Northwest, Arizona, Aruba, Bahamas, Bangladesh, Belize, Benin, Bolivia, Borneo, Botswana, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Burkina, Burundi, Cabinda, Cameroon, Cape Provinces, Caprivi Strip, Cayman Is., Central African Repu, Chad, China South-Central, China Southeast, Christmas I., Colombia, Congo, Costa Rica, Cuba, Delaware, District of Columbia, Djibouti, Dominican Republic, Ecuador, El Salvador, Equatorial Guinea, Eritrea, Ethiopia, Florida, Free State, French Guiana, Gabon, Galápagos, Georgia, Ghana, Guatemala, Guinea, Gulf of Guinea Is., Guyana, Hainan, Haiti, Honduras, Illinois, India, Indiana, Ivory Coast, Jamaica, Jawa, Kentucky, Kenya, KwaZulu-Natal, Laccadive Is., Laos, Leeward Is., Liberia, Louisiana, Madagascar, Malawi, Malaya, Mali, Mauritania, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Michigan, Mississippi, Missouri, Mozambique, Myanmar, Namibia, Nebraska, Nepal, Netherlands Antilles, New Caledonia, New Guinea, New Jersey, New Mexico, New South Wales, Nicaragua, Niger, Nigeria, Northern Provinces, Northern Territory, Oklahoma, Oman, Pakistan, Panamá, Paraguay, Pennsylvania, Peru, Philippines, Puerto Rico, Queensland, Rwanda, Samoa, Saudi Arabia, Senegal, Sierra Leone, Socotra, Somalia, South Australia, South Carolina, Southwest Caribbean, Sri Lanka, Sudan, Sulawesi, Suriname, Swaziland, Taiwan, Tanzania, Tennessee, Texas, Thailand, Togo, Trinidad-Tobago, Turks-Caicos Is., Uganda, Uruguay, Vanuatu, Venezuela, Venezuelan Antilles, Vietnam, Virginia, Wallis-Futuna Is., West Himalaya, West Virginia, Western Australia, Windward Is., Yemen, Zambia, Zaïre, Zimbabwe

Introduced into:

Arkansas, Assam, Bermuda, Cambodia, Cook Is., Fiji, Gambia, Hawaii, Lesser Sunda Is., Marianas, Mauritius, Nauru, New York, Nicobar Is., Réunion, Seychelles, South China Sea, Tokelau-Manihiki

Ruellia Plum. ex L. appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 1990 Botteri, M. [492], Mexico K000064386
Harley, R.M. [16850], Brazil K001032635
Harley, R.M. [15382], Brazil K001032636
Harley, R.M. [21371], Brazil K001032637
Harley, R.M. [21371], Brazil K001032638
Harley, R.M. [16850], Brazil K001032645
Harley, R.M. [22458], Brazil K001032715
Harley, R.M. [22458], Brazil K001032716
Harley, R.M. [24308], Brazil K001032725
Harley, R.M. [16758], Brazil K001032743
Harley, R.M. [s.n.], Brazil K001032747
Harley, R.M. [27722], Brazil K001046159
Williams, R.O., Tanzania 2935.000
Trail, J.W.H. [644], Brazil K001032720
Harley, R. [6004], Brazil K001032721
Taylor, N.P. [422], Mexico K000064377
Beentje, H.J. [4593], Madagascar 60561.000
Rico, L. [2013], Mexico K000265995
Gilbert [57], Paraguay K001032689
Santos, T.S. [1955], Brazil K001032730
Giulietti, A.M. [1202], Brazil K001032728
Sakuragui, C.M. [CFCR 15173], Brazil K001046160
Coradin, L. [6022], Brazil K001032746
Lucena, M.F.A. [45], Brazil K001032647
Oliveira, M. [63], Brazil K001032640
Gomes, A.P.S. [55], Brazil K001032646
Lira, S.S. [20], Brazil K001032723
Heringer, E.P. [16011], Brazil K001046154
Andrade, K. [205], Brazil K001032644
Preston, T.A. [s.n.], Brazil K001032692
Villarouco, F.M.O. [124], Brazil K001032722
Bolland, G. [13], Brazil K001032738
Fonseca, M.L. [1049], Brazil K001032693
Brooks, R.R. [639], Brazil K001046161
Krukoff, B.A. [6022], Brazil K001032727
Krukoff, B.A. [4971], Brazil K001046152
Krukoff, B.A. [4971], Brazil K001046153
Krukoff, B.A. [4708], Brazil K001046158
Bourgeau, M. [2903], Mexico K000064180
Bourgeau, M. [2859], Mexico K000064385
Mori, S. [10257], Brazil K001046162
Teixeira, L.O.A. [319], Brazil K001032745
Weir, J. [s.n.], Brazil K001032717
Sellow [788], Brazil K001032690
Sellow [s.n.], Brazil K001032744
Tschá, M.C. [302], Brazil K001032641
Tschá, M.C. [313], Brazil K001032642
Figueirêdo, L. [215], Brazil K001032724
Melo, M.R.C.S. [215], Brazil K001032643
Forzza, R.C. [4058], Brazil K001032634
Félix, L.P. [1640], Brazil K001032734
Saint-Hilaire, A. [494], Brazil K001032732
Saint-Hilaire, A. [304], Brazil K001032733
Prance, G.T. [16778], Brazil K001032691
Prance, G.T. [58653], Brazil K001032719
Prance, G.T. [14100], Brazil K001032735
Prance, G.T. [12304], Brazil K001032736
Prance, G.T. [14583], Brazil K001032740
Strudwick, J.J. [3044], Brazil K001032741
Mexia, Y. [5352], Brazil K001032742
Lemos, J.R. [242], Brazil K001032729
Burchell [8928], Brazil K001032639
Burchell [7417], Brazil K001032726
Burchell [8064], Brazil K001032739
Burchell [5951], Brazil K001046155
Burchell [5951], Brazil K001046156
Burchell [8941-2], Brazil K001046157
Glaziou [17173], Brazil K001032718
Glaziou [15296], Brazil K001032731
Glaziou [18397], Brazil K001032737

First published in Sp. Pl.: 634 (1753)

Accepted by

  • Tripp, E.A. & McDade, L.A. (2012). New synonymies for Ruellia (Acanthaceae) of Costa Rica and notes on other neotropical species Brittonia 64: 305-317. New York Botanical Garden.


Flora of West Tropical Africa

  • —F.T.A. 5: 44.

Flora of Somalia

  • Flora Somalia, (2000) Author: by M. Hedrén [updated by M. Thulin 2008]

Flora of Tropical East Africa

  • F.T.A. 5: 44 (1899)
  • DC., Prodr. 11: 143 (1847)
  • Sp. Pl.: 634 (1753)
  • G.P. 2: 1077 (1876)

Flora of Somalia
Flora of Somalia

Flora of Tropical East Africa
Flora of Tropical East Africa

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