Blumea 59, 2014: 19–25 www.ingentaconnect.com/content/nhn/blumea RESEARCH ARTICLE http://dx.doi.org/10.3767/000651914X681964 New species of Maerua (Capparaceae) from Angola J.A. Abreu1, E.S. Martins1, L. Catarino1, 2 Key words Abstract Genus Maerua has around 60 species represented on the African continent, of which three have been reported for Angola. Two new species of Maerua (Capparaceae) from Angola are here described. Both are closely Angola similar to M. juncea subsp. juncea, being distinguished by floral traits such as the receptacle, androphore and Capparaceae gynophore (M. pintobastoae) or leaf traits such as venation, as well as size and shape of the ovary and disc shape endemism (M. mendesii). A key for Maerua species occurring in Angola is provided, as well as a table summarizing and com- Maerua paring the morphological characters for the new species and similar African species. With the description of these Southern Africa two new species, the genus Maerua comprises five species in Angola. taxonomy Resumo O género Maerua tem cerca de 60 espécies representadas no continente Africano, das quais 3 foram já reportadas para Angola. São aqui descritas duas novas espécies de Maerua (Capparaceae) de Angola, ambas estreitamente semelhantes com M. juncea subsp. juncea, da qual diferem por carateres florais como o recetáculo, andróforo e ginóforo (M. pintobastoae) ou por caracteres foliares como nervação, bem como tamanho e forma do ovário e forma do disco (M. mendesii). Apresenta-se uma chave das espécies de Maerua que ocorrem em Angola, bem como uma tabela comparativa das características morfológicas de cada uma das novas espécies com espé- cies africanas similares. Considerando as novas espécies descritas, o género Maerua compreende cinco espécies com ocorrência confirmada em Angola. Published on 14 May 2014 INTRODUCTION M. angolensis DC. (1824: 254) (including the variety heterophyl­ la), M. buxifolia (Welw. ex Oliv.) Gilg & Gilg-Ben. (Gilg & Bene- The family Capparaceae belongs to the order Brassicales and dict 1915: 249), M. gilgii Schinz (1903: 668) and M. welwitschii is closely related to the Cleomaceae and Brassicaceae (APG Gilg & Gilg-Ben. (Gilg & Benedict 1915: 250). In a note on the III 2009). In the older family arrangements Capparaceae s.l. Maerua species in Angola, Gonçalves (1962) also reported the includes Cleomaceae but molecular data support the recogni- occurrence of four species in the country: M. angolensis DC., tion of three monophyletic families, Capparaceae s.str., Cleo­ M. buxifolia, M. gilgii and M. parvifolia Pax (1894: 135). This maceae and Brassicaceae, instead of an all-encompassing author considered M. welwitschii as conspecific to M. buxifolia. Brassicaceae or a paraphyletic Capparaceae s.l. (Iltis et al. Later, Figueiredo & Smith (2008) reported only three species to 2011). occur in the country: M. angolensis, M. buxifolia and M. parvi­ Capparaceae s.str. is a tropical and subtropical family of herbs, folia. From the previously listed species we here accept only trees, shrubs and some lianas, with about 417 species (APG the ones mentioned by Figueiredo & Smith (see the taxonomic III 2009). notes below), adding two new species with the current study. The only taxonomic treatment of the Capparaceae from Angola We consider that the taxonomy of this genus in Angola is unre- was published in the first volume of the incomplete work Con- solved and the number of Maerua species in the country can be spectus Florae Angolensis (Exell & Mendonça 1937), which was an underestimated figure due to the lack of recent taxonomic considered as ‘considerably out-of-date’ by Brenan a few dec- work on the family. When we were digitizing the Angolan speci- ades later (1978). Recent work on the family includes the study mens of Capparaceae at LISC for the project IMBAMBA, several of the phylogeny by Hall et al. (2002). A review by Figueiredo & unusual specimens called our attention. These specimens were Smith (2008) updated the family treatment for Angola, listing a attributed by E.J. Mendes in 1973 to two new undescribed spe- total of 40 taxa in seven genera. A recent study on Capparaceae cies. A detailed study of the specimens and their comparison to and Cleomaceae endemic to Angola was carried out by Abreu specimens of other taxa from the genus Maerua, from Tropical et al. (2013). Despite these works, as already stated by Hall et Africa, Southern Africa and Zambesian Region, allowed us to al. (2002) the family still needs taxonomic study. confirm that these do not match any other published taxa and Maerua Forssk. (Forsskäl 1775: 104) is a genus with a wide dis- represent two undescribed species, which we name Maerua tribution, ranging from Tropical and Southern Africa to Tropical pintobastoae and Maerua mendesii. The species morphologi- Asia (Hall 2008), with approximately 60 species represented on cally most similar to the new species is M. juncea Pax (1891: the African continent (African Plants Database 2012). Exell & 302) subsp. juncea, which is distinguished by floral traits such Mendonça (1937) accepted four species of Maerua for Angola: as the receptacle, androphore and gynophore (M. pintobastoae) or leaf traits such as venation, as well as size and shape of the 1 Jardim Botânico Tropical, Instituto de Investigação Científica Tropical; Trav. ovary (M. mendesii). As summarized in Table 1, M. pintobastoae Conde da Ribeira 9, 1300-142 Lisboa, Portugal; differs from other similar species not recorded for Angola by corresponding author e-mail: [email protected]. traits such as seed size, number of stamens and receptacle 2 CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, Universidade do Porto, 4485-601 Vairão, (M. kaokoensis Swanepoel 2006: 81), fruit shape, texture and Portugal. size (M. nervosa Oliv. 1868: 84) and in having a much shorter © 2014 Naturalis Biodiversity Center You are free to share - to copy, distribute and transmit the work, under the following conditions: Attribution: You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Non-commercial: You may not use this work for commercial purposes. No derivative works: You may not alter, transform, or build upon this work. For any reuse or distribution, you must make clear to others the license terms of this work, which can be found at http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode. Any of the above conditions can be waived if you get permission from the copyright holder. Nothing in this license impairs or restricts the author’s moral rights. 20 Table 1 Relevant morphological characters of M. pintobastoae, M. mendesii and other African morphologically related species. M. pintobastoae M. mendesii M. juncea subsp. juncea M. kaokoensis Swanepoel* M. schinzii Pax M. angolensis M. nervosa (Hochst.) Oliv. M. salicifolia Wild.* Leaf size (l by w) – 19–44 by 1–5 mm 22–75 by 5–20 mm (16–)25–60(–95) by 20–60 by 15–70 by 13–42 mm 25–60 by 15–35 mm 60–100 by 15–25 mm (5–)7–17(–30) mm 11–35(–73) mm Leaf shape – linear to strictly linear, narrowly elliptic, lanceolate, oblanceolate, elliptic to ovate, rarely elliptic or ovate, rarely elliptic to obovate narrowly elliptic lanceolate elliptic, ovate or rarely narrowly elliptic to elliptic, oblanceolate obovate obovate linear-elliptic, linear-oblong or oblong Venation with a brighter marginal 4–7 lateral veins 4–10 lateral veins 4–5 lateral veins, 4–5 lateral veins, 4–6 lateral veins, veins in 4–6 pairs vein; sometimes with looping before looping before gathered in submarginal 1–2 pairs of lateral veins the margin the margin vein Stamens number 20–30, 12–18 mm 19–31, 17–27 mm 20–45, up to 21 mm 32–42, 18–35 mm 30–70, 14–16 mm 40–60, 20–26 mm 18–30, c. 20 mm c. 30, around 25 mm and length Gynophore (l) 8–10 mm 19–23 mm 19–22 mm 18–28 mm 15–20 mm 35–40 mm 21–23 mm c. 22 mm Seed diameter 1.1–1.7 mm; irregularly not present in the up to 7 mm; subglobose, 4–5 mm; globose, testa 5 mm; subglobose, 5–9 mm; globose, c. 5 mm; subglobose, c. 5 mm; irregularly ovate, and shape angular, testa minutely plants studied angular; testa rugose faintly granulate granulate testa smooth testa verrucose testa rugose granulate Androphore (out of 1.4–2.0 mm; 1.0–2.9 mm; usually equalling the equal to or extending to equal to extending to extending 2 mm above 2 mm; 7 mm total exserted from the the receptacle; total 4.2–5.4 mm total 4.9–5.4 total receptacle 2.5 mm above receptacle; 2 mm above the the receptacle receptacle; 7–8 mm total length) 11–13 mm total receptacle; 5–7 mm total Petals (l by w) 3.7–8.0 by 2.0–3.4 mm, 5.0–7.0 by 2.5–3.8 mm, 3.5–9.0 by 2.0–4.5 mm, absent absent absent 2.3–7.0 by 1.2–5.0 mm, c. 9.0 by 3.5 mm, narrowly lanceolate to obovate ovate elliptic, ovate, broadly elliptic elliptic ovate or rotund Sepals (l by w) 6–11 by 3.0–4.8, elliptic 16–29 by 4.5–7.0 mm, 17–19 by 5–6 mm, elliptic 9.8–14.5 by 4.0–5.7 mm, 11–15 by 5–8 mm, 15–18 by 6–8 mm, elliptic 9–10 by 5–8 mm, elliptic c. 20 by 6 mm, narrowly to oblong-elliptic lanceolate often somewhat cucullate elliptic-obovate or ovate, often cucullate to broadly elliptic, navicular oblong-elliptic Pedicel up to 10.5 mm 5–10 mm up to 35 mm 4–13 mm 8–25 mm 10–15 mm 10–20 mm up to 30 mm Ovary 2.8–3.5 mm; oblong to 5.0–7.9 mm; linear, 2.4–5.0 mm; ovoid-oblong 4.8–7.1 mm; cylindrical 5–10 mm; ellipsoid- 8–10 mm; cylindrical c.