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8. Drosera madagascariensis DC. — Fig. 10 Drosera madagascariensis DC. (1824) 318; Diels (1906) 98; G.C.C. Gilbert (1951) 554; Keay (1954) 121; J.R. Laundon (1959) 5; Oberm. (1970) 200; J.R. Laundon (1978) 68; Troupin (1978) 307; Akoègn. et al. (2006) 539; A.S.Rob. et al. (2017) 1426. — Type: Lambert s.n. (holo G-DC), Madagascar, 1819. Drosera congolana Taton (1945b) 310; G.C.C. Gilbert (1951) 552. — Type: J. Bequaert 7191 (holo BR), DRC, Leopoldville, 29 Mar. 1915 Perennial, caulescent herb. Stems up to 25 cm long, rarely acau- lescent (see Note), c. 1 mm diam, only apical part of the stem self-supporting, glabrous or sparsely pilose (Fig. 10b). Leaves evenly spaced along the stem, alternate to spirally arranged, occasionally clustered, erect, older leaves reflexed; stipules oblong, 2–6(–8) by c. 1 mm, membranous, lacerated apically, ferrugineous; lamina obovate, elliptic or spathulate, 0.4–1.1 (–3) cm by 2–7 mm, bearing tentacles adaxially and around the margins, almost glabrous to pilose abaxially (Fig. 10a); petiole linear, 0.6–2(–3) cm by 0.3–1 mm, glabrous to pilose. Inflorescences cymose, with 2–15 flowers, axillary; peduncles 1–3 together; 9–55 cm long, arising laterally, ascending, basally particularly curved, glabrous, glandular or pilose; bracts linear to spathulate, 2–3 mm long, sparsely pilose, caducous; pedicels 1–10 mm long, glandular or pilose. Sepals 5, elliptic to oblonglanceolate, 4–7 by 1–2 mm, connate at the base, apex acute or obtuse, glandular and/or pilose. Petals 5, obovate, 5–12 by 3.5–6 mm, pink or purple. Stamens 5; filaments 2–5 mm long. Pollen in tetrads, tetrads c. 45 µm diam, single grains c. 30 µm diam, echinate (Fig. 10e), echini broadly conical, c. 2 mm long, of medium density with short clavate sculptural elements between them. Pistil: ovary subglobose to ovoid, c. 2 by 1–1.5 mm, glabrous; styles 3, c. 2 mm long, 2-partite to the base, apices clavate, white to pink. Seeds fusiform, 0.7–1 by c. 0.2 mm, brownish black, apiculate, testa reticulate. Distribution — Widespread in tropical Africa, South Africa, Madagascar (Fig. 10c). Habitat & Ecology — Perennially wet habitats (swamps, marshes, river and lake shores, perennially wet places in seasonally dry wet-savannahs). Additional specimens (see Fig. 10d for province map). ANGOLA, Bié, Silva Porto – Andulo, km 35, S12°09' E16°45', alt. 1700 m, 15 Mar. 1973, P. Bamps et al. 4153 (BR); Cusseque – TFO core site, plain, alluvial plain, fire in last dry season, S13°42' E17°6', alt. 1515 m, 29 Oct. 2011, R. Revermann 132779 (HBG), M. Finckh 132768 (HBG); Cuando Cubango, Baixo Cubango, 179 km von Cuangar in Richtung Caiundo, sumpfiges Gelände am Rio Cubango, Moorboden, alt. 1070 m, 29 Jan. 1952, H. Hess 52/509 (ZT); Menongue, Vila Serpa Pinto, pr. da confluencia do Camumbé com o Cuebe, alt. 1420 m, 12 Feb. 1960, E.J. Mendes 2482 (COI); Cuito- Cuanavale, confluencia dos rios Tchiengo com o Cuito, alt. 1280 m, 3 Mar. 1960, E.J. Mendes 2811 (COI); Cuito-Cuanavale, Longa, Cuango, vale do Cuango, alt. 1370 m, 18 Mar. 1960, E.J. Mendes 3185 (BR, P); Huambo, Mission de Humabo, Nov. 1942, C. Tisserant A310 (COI); Chianga, alt. 1700 m, 11 June 1962, Teixeira & Andrada 6446 (COI); Arredores de Nova Lisboa, Chiva,alt. 1700 m, 19 Mar.1971, M. de Silva 3480 (BR, COI); Huíla, Serra de Chella, aux environs de Huíla, alt. 1850 m, 1937, H.Humbert 16686 (P); Entlang einem Bache auf dem Hochplateau von Bimbe bei Humpata, alt. 2300 m, 9 Sept. 1950, H. Hess 50/188 (ZT); Lubango, Chipia, ao km 7 da picada para Missao do Munhino, 11 May 1971, A. Borges 248 (BR, COI); Lunda, Vila Henrique de Carvalho, rio Chicapa, alt. 1100 m, 16 Apr. 1937, A.W. Exell & F.A. Mendon ҫa 636 & 644 (COI); Malanje, Quimbango, Congolo, Reserca da Palanca Negra Gigante (ou Reserva do Luando), 7 June 1970, G. Barbosa et al. 11963 (COI); Uíge, near small lagoon, through which water flows, S6°1' E15°24',alt. 803 m, 25 Feb.2017, T. Lautenschläger 2017-02-139 & 2017-02-111 (DR). – DRC, Equateur, Ilema (Terr.Coquilhat- ville), 21 Mar. 1958, Èvrard 3748 (BR); Haut-Katanga, Le long de la route Mitwaba – Manono,à 11 km de Mitwaba – Sermikat, 21 Apr.1997, Symoens 3612 (BR); Ituri, Nioka (Mahagi), alt. 1700 m, 29 July 1960, D. Froment 758 (BR, P); Kinshasa, Route Soo-Ndunu, Maluku, 5 May 1971, H. Breyne 2190 (BR); Kongo Central, Binza, Route de Ngidinga à Kimvula, Territoire de Madimba, 15 Feb. 1960, P. Compere 1479 (BR); Kilenfu-Leg-Boko, S5°01' E15°11', 10 Feb. 2014, Nsimundele 2723 (BR); Kwango, Nto Mbombo, terr. Popokabaka, 9 Jan. 1959, L. Pauwels 1208 (BR); Tangi, alt. 700 m, Jan. 1930, J. Lebrun 127 (BR); Lualaba, Shaba, Kolwezi – Luena, km 114, Riv. Mutendele, 20 Jan.1986, Bamps & Malaisse 8222 (BR); Environs de Kolwezi, vallée de la Kanamwamfwe, 23 Aug. 2004, Malaisse & Kisimba 134 (BR); Sud-Kivu, Massif du Kahuzi, Env. du 43 km de la route Bukavu-Walikale, alt. 2200 m, 22 Apr. 1970, J. Lambinon 78/228 (BR); Tanganyika, Kilunga (Marungu), Apr. 1945, L. Dubois 1416 (BR); 3 km a l’W. de Kasiki, Plateau des Marungu, alt. 2000 m, 12 June 1969, S. Lisowski et al. 6139 (BR); Mare Mufufu, Plateau des Marungu, alt. 1900 m, 14 June 1969, S. Lisowski et al. 6606 (BR). Note — A very variable species with stems occasionally suppressed and dwarf forms (these show often suborbicular to elliptic leaves and a reddish colour). Hybridisation with D. elongata and D. affinis is possible. Plants in South Africa with suppressed stems (D. madagascariensis var. major Burtt Davy) were synonymized with D. curvipes Planch. and plants from southern Africa were synonymised with D. ramentacea Burch. ex DC. Both D. curvipes and D. ramentacea are now mostly accepted as separate taxa (Robinson et al. 2017). The distinct diagnostic features of D. madagascariensis (reflexed leaves, strongly curved base of inflorescence; Fig. 10) make most of the specimens easy to determine. However, the species is known to be highly variable in height, stem length and leaf size and shape depending on the habitat and available nutrients (Robinson et al. 2017). The dwarf form of D. madagascariensis (e.g., H. Breyne 4636) can be easily mistaken for D. burkeana or D. pilosa. To distinguish between these species leaf shape, seed shape and morphology and pollen morphology could be used. Furthermore, relatively large and robust specimens occur. Three large specimens are doubtfully determined as D. madagascariensis (partly H. Hess 50/188, A.W. Exell & F.A. Mendon ҫa 644 and 636) showing very large obovate to elliptic laminae, densely pilose stems, scapes and leaves and more or less erect to strongly curved inflorescences., Published as part of Rjosk, A., Neinhuis, C., Monizi, M. & Lautenschläger, T., 2022, Synopsis of the genus Drosera (Droseraceae) in Angola and the Democratic Republic of the Congo, pp. 1-14 in Blumea - Biodiversity, Evolution and Biogeography of Plants 67 (1) on pages 10-11, DOI: 10.3767/blumea.2022.67.01.03, http://zenodo.org/record/7679465, {"references":["Diels L. 1906. Droseraceae. In: Engler A (ed), Das Pflanzenreich IV. 112. Engelmann, Leipzig.","Gilbert G. 1951. Droseraceae. In: Flore du Congo Belge et du Ruanda-Urundi. Institut national pour l'etude agronomique du Congo Belge.","Keay RWJ. 1954. Flora of West Tropical Africa. Crown Agents for Oversea Governments and Administrations, London.","Laundon JR. 1959. Droseraceae. In: Hubbard CE, Milne-Redhead E (eds), Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London.","Laundon JR. 1978. Droseraceae. In: Launert E (ed), Flora Zambesiaca. Flora Zambesiaca Managing Committee, London.","Troupin G. 1978. Flore du Rwanda. Musee Royal de l'Afrique Centrale, Tervuren.","Taton A. 1945 b. Drosera congolana. Bulletin du Jardin Botanique de l'Etat a Bruxelles: 310.","Robinson A, Gibson R, Gonella P, et al. 2017. Drosera of the World - volume 3, Latin America, Africa. Redfern Natural History Productions, Poole."]}

Rabarimanarivo, M.N., B. Ramandimbisoa, N.H. Rakotoarivelo, P.B. Phillipson, S. Andriambololonera, M.W. Callmander & S. Porembski (2019). The extraordinary botanical diversity of inselbergs in Madagascar. Candollea 74: 65–83. In English, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2019v741a8Inselbergs are isolated mountains, mainly granitic or gneissic rock outcrops rising abruptly above surrounding plains. Malagasy inselbergs are often dome-shaped and occur in varying degrees of isolation, but they sometimes form inselberg landscapes, which comprise dozens of individual outcrops. Despite being typical landscape features on Madagascar's high plateau, little data are available on their detailed plant cover. Recent extensive fieldwork, which was conducted between 2010 and 2014, mainly on the central plateau, has resulted in a better knowledge about the floristic composition and habitats of Malagasy inselbergs. The most speciose vascular plant genera were Cynorkis Thouars (18), Cyperus L. (15) and Euphorbia L. (14). Malagasy inselbergs are centres of diversity for succulents (notably species of the genera Aloe L., Euphorbia and Kalanchoe Adans.), carnivorous plants (species of Drosera L. and Utricularia L.) and resurrection plants (notably species of Xerophyta Juss.). The most speciose habitat types were ephemeral flush vegetation and monocotyledonous mats. The latter habitat supports a large number of succulents and resurrection plants. In total 724 taxa out of 338 genera and 107 families have been recorded. Moreover, the variability in floristic composition between different regions is remarkable. Detrimental human impacts include quarrying, grazing, fire and the collection of plants for ornamental purposes (species of Pachypodium Lindl. and Orchidaceae) and as medicine (species of Aloe, Drosera madagascariensis DC., Myrothamnus moschatus (Baill.) Baill.). For the first time, recommendations are made for the conservation of Malagasy inselbergs.

The antiinflammatory effects of ethanol and aqueous extracts from Drosera rotundifolia and from Drosera madagascariensis were compared in vivo in the HET-CAM assay. Both extracts from D. rotundifolia and the ethanol extract from D. madagascariensis showed remarkable efficacy at doses of 500 microg/pellet. The inhibition of the inflammation by the extracts was stronger than that by 50 microg hydrocortisone/pellet. In contrast, there was only a very weak effect observed at a dose of 500 microg/pellet of the water extract from D. madagascariensis. The chemical analyses of the extracts showed that the effect cannot be attributed to naphthoquinones, but might be due to flavonoids. Ellagic acid obviously plays an important role in the antiangiogenic effect of the Drosera extracts.