- Family:
- Acanthaceae Juss.
Duosperma Dayton

[FSOM]
M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS
- Morphology General Habit
- Shrubs or subshrubs
- Morphology Leaves
- Leaves entire or crenate-dentate with truncate apex
- Morphology Reproductive morphology Inflorescences
- Flowers solitary or clustered at upper nodes, subtended by leaf-like bracts and bracteoles
- Morphology Reproductive morphology Flowers Calyx
- Calyx of 4 lobes, upper and lower lobes relatively wide, the lower one 2-fid, lateral lobes small, linear
- Morphology Reproductive morphology Flowers Corolla
- Corolla ± 2-lipped
- Morphology Reproductive morphology Flowers Androecium Stamens
- Stamens 4; anthers 2-celled
- Morphology Reproductive morphology Fruits
- Capsule 2-seeded
- Morphology Reproductive morphology Seeds
- Seeds flat, orbicular, with mucilaginous hairs especially along the margin.
- Distribution
- Genus of some 25 species in tropical and southern Africa, and in Yemen.
[FTEA]
Acanthaceae (part 2), Kaj Vollesen. Flora of Tropical East Africa. 2008
- Morphology General Habit
- Perennial or shrubby herbs or shrubs, with usually conspicuous linear cystoliths (especially on calyx); stems terete to distinctly quadrangular; bark on older branches usually peeling off in flakes or strips
- Morphology Leaves
- Leaves opposite, with strong unpleasant smell when crushed; basal part of petiole forming a stipule-like sheath around the stem
- Morphology Reproductive morphology Flowers
- Flowers subsessile or petiolate, solitary or in condensed axillary cymes which sometimes merge into large panicles; bracteoles usually large and conspicuous, often foliaceous
- Morphology Reproductive morphology Flowers Calyx
- Calyx leathery, 5-lobed, fused in basal part, splitting in fruit; lobes lanceolate to triangular, with strong rib-like central vein and with scarious margins, dorsal lobe usually distinctly longer and wider than the rest, 2 ventral lobes fused higher up
- Morphology Reproductive morphology Flowers Corolla
- Corolla contorted in bud, distinctly 2-lipped; tube cylindric at base, widening into a dictinct throat which is hairy ventrally; upper lip 2-lobed, erect, sometimes slightly hooded, lower lip 3-lobed, deflexed, lobes all similar, but wider in lower lip, lower lip pleated at base, with or without long stiff hairs
- Morphology Reproductive morphology Flowers Androecium Stamens
- Stamens 4, inserted just inside cylindric part of tube, didynamous (longer pair 1–2 mm longer than short pair), held under upper lip, the two short stamens occasionally reduced to staminodes; filaments fused with tube, fused part running like two puberulous longitudinal ridges to base of tube, free part of each long and short filament fused at base; anthers 2-thecous, thecae oblong, rounded or apiculate at both ends, never with spurs
- Morphology Reproductive morphology Flowers Gynoecium Ovary
- Ovary with 1–2 ovules per locule.
- Morphology Reproductive morphology Flowers Gynoecium Style
- Style filiform, with upwardly directed hairs.
- Morphology Reproductive morphology Flowers Gynoecium Stigma
- Stigma lobes 2, linear, equal or dorsal about half the length of ventral
- Morphology Reproductive morphology Fruits
- Capsule (1–)2-seeded, ellipsoid-obovoid, woody, glossy, laterally compressed, usually glabrous, valves sulcate dorsally; retinaculae strong, hooked
- Morphology Reproductive morphology Seeds
- Seed discoid, ovoid to orbicular in outline, with hygroscopic hairs.
- Note
- Duosperma is morphologically very similar to Dyschoriste and Hygrophila but palynological work (Vollesen l.c.) strongly implies that it is closer to Mellera, Mimulopsis and Eremomastax. It differs from Dyschoriste and Hygrophila in the laterally compressed 2-seeded capsule and in having a style with both stigma lobes well-developed. The large conspicuous bracteoles also provide a useful spot-character. The capsules usually persist on the plant until next rainy season. The apical part (base of style) is thickened and slightly bulbous and only tardily dehiscent.
- Distribution
- Range: 26 species in eastern and southern tropical Africa from Somalia and S Ethiopia to Botswana and Angola. One species extends to Yemen. Particularly diverse from central and SW Tanzania into N Zambia and SE Congo.
Native to:
Angola, Botswana, Caprivi Strip, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Northern Provinces, Somalia, Sudan, Tanzania, Uganda, Yemen, Zambia, Zaïre, Zimbabwe
- Duosperma actinotrichum (Chiov.) Vollesen
- Duosperma clarae Champl.
- Duosperma crenatum (Lindau) P.G.Mey.
- Duosperma cuprinum Brummitt
- Duosperma densiflorum (C.B.Clarke) Brummitt
- Duosperma dichotomum Vollesen
- Duosperma fanshawei Brummitt
- Duosperma fimbriatum Brummitt
- Duosperma glabratum Vollesen
- Duosperma grandiflorum Vollesen
- Duosperma kaessneri (S.Moore) Vollesen & I.Darbysh.
- Duosperma kilimandscharicum (Lindau) Dayton
- Duosperma latifolium Vollesen
- Duosperma livingstoniense Vollesen
- Duosperma longicalyx (Deflers) Vollesen
- Duosperma nudantherum (C.B.Clarke) Brummitt
- Duosperma parviflorum Hedrén & Vollesen
- Duosperma porotoense Vollesen
- Duosperma quadrangulare (Klotzsch) Brummitt
- Duosperma rehmannii (Schinz) Vollesen
- Duosperma sessilifolium (Lindau) Brummitt
- Duosperma stoloniferum Vollesen
- Duosperma subquadrangulare Vollesen
- Duosperma tanzaniense Vollesen
- Duosperma trachyphyllum (Bullock) Dayton
- Duosperma transvaalense (Schinz) Vollesen
Duosperma Dayton appears in other Kew resources:
First published in Rhodora 47: 262 (1945)
Accepted by
- Govaerts, R. (2000). World Checklist of Seed Plants Database in ACCESS D: 1-30141.
Literature
Flora of Somalia
- Flora Somalia, Vol 1, (1993) Author: by M. Thulin [updated by M. Thulin 2008]
- Vollesen in Kew Bull. 61: 289–351 (2006).
Flora of Tropical East Africa
- Brummitt K.B. 29: 411 (1974)
- Dyer, Gen. S. Afr. Fl. Pl. 1: 587 (1975)
- Rhodora 47: 262 (1945)
- Vollesen K.B. 62: 289 (2006)
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Flora of Somalia
Flora of Somalia
http://creativecommons.org/licenses/by-nc-sa/3.0
-
Flora of Tropical East Africa
Flora of Tropical East Africa
http://creativecommons.org/licenses/by-nc-sa/3.0
-
Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2022. 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 2022. 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