Plant Syst Evol DOI 10.1007/s00606-017-1429-4 ORIGINAL ARTICLE Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga ecoregion in Brazil Lidian R. de Souza1,3 • Daniela S. Carneiro-Torres1 • Marileide D. Saba2 Francisco de Assis R. dos Santos1 • Received: 13 February 2017 / Accepted: 19 May 2017 Ó Springer-Verlag Wien 2017 Abstract This study dealt with six species of Acalyphoideae and 18 species of Euphorbioideae occurring in the Caatinga ecoregion, with emphasis on endemic species. Pollen samples were obtained from herbarium specimens and were acetolysed and analysed via light and scanning electron microscopy. The pollen of three genera of Acalyphoideae was medium to large, 3-colporate or 3-colpate, with an echinate-perforate exine that was reticulate, bireticulate, and microreticulate. The six genera of Euphorbioideae studied exhibited pollen grains that were small, medium and large; 3-colporate with margines; and an exine with microreticulate, microreticulate-rugulate, microreticulate-caveate, and reticulate ornamentation. The pollen characteristics were more variable in the Acalyphoideae compared to the relatively homogeneous Euphorbioideae. This study provides new data and interpretations of the pollen morphology of two subfamilies of the Euphorbiaceae of the Caatinga ecoregion in Brazil. Keywords Endemism
Malpighiales
Neotropics
Palynology
Pollen grains Handling Editor: Louis P. Ronse De Craene. & Lidian R. de Souza lidian.bio@gmail.com 1 Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Feira de Santana, BA, Brazil 2 Universidade do Estado da Bahia, Campus VII, Senhor do Bonfim, BA, Brazil 3 Departamento de Ciências Biológicas, Laboratório de Micromorfologia Vegetal, Universidade Estadual de Feira de Santana, Av. Universitárias/n, Feira de Santana, BA 44031-460, Brazil Introduction The Caatinga ecoregion possibly originated from climatic and geological changes that occurred in South America during the Late Pleistocene (Prado 2003). Thus, it belongs to the Pleistocene Arc (Prado and Gibbs 1993), which forms a phytogeographic unit: the seasonally dry tropical forests (SDTF) that are disjointedly distributed throughout the southern portion of the American continent (Prado 2000). Various hypotheses attribute the disjointed distribution of some plant groups (Leguminosae) in different areas of SDTF to habitat fragmentation, while the occurrence of endemic species is attributed to the isolation of populations (Cardoso and Queiroz 2010). The Caatinga biome occupies a large area of approximately 734,000 km2, which spreads throughout the majority of the semi-arid region of north-eastern Brazilian (Rodal and Sampaio 2002). Water deficiencies caused by high rates of evapotranspiration combined with the temporal irregularities in the distribution of rain are the main determining factors for the existence of this biome (Queiroz 2008). Andrade-Lima (1982) noted that the level of endemism in the Caatinga area was low. However, it is known that the Caatinga has significant richness compared to other dry forests distributed throughout South America, presenting taxa with varied and numerous habitats (Prado 2003); additionally, it is one of the areas with the highest endemism of dry forests around the world (Pennington et al. 2006). Nevertheless, 30% of this ecosystem has already been modified by anthropic action, making it the third most altered Brazilian biome (Tabarelli and Vicente 2002). Among the ten families of Angiosperms with the largest number of representatives that Biome has, Euphorbiaceae ranks fourth (Forzza et al. 2010). It is considered one of the 123 L. R. de Souza et al. most diverse and important families from both a morphological and taxonomic point of view (Webster 1987). The group also stands out for its highly specific richness, high morphological diversity and phytochemicals, and economic relevance (Radcliffe-Smith 2001; Wurdack et al. 2005). Among Euphorbiaceae subfamilies, only Acalyphoideae, Crotonoideae and Euphorbioideae have representatives in the Caatinga and have endemic taxa (Flora do Brasil 2017). Peroideae has no endemic species in this ecoregion (Bigio et al. 2015), and Cheilosoideae is restricted to Southeast Asia (Wurdack et al. 2005). Euphorbioideae is considered to be monophyletic. It is distinctive for gathering more complex floral morphological types (cyathium) and for being considered a more derived group that is composed of 53 genera, five tribes (Wurdack et al. 2005) and approximately 2000 species (Webster 1987, 1994). Its species have white and milky latex, highly reduced staminate flowers with overlapping or vestigial sepals, absent petals, and pollen grains with a reticulate-perforate exine (Webster 1994; Wurdack et al. 2005). The pollen grains of this species are also characterized as oblate to prolate, with 3-colporate colpi that are generally marginate and tectate-perforate (Radcliffe-Smith 2001). Acalyphoideae has 14 tribes, 110 genera, and approximately 1500 species (Barberá et al. 2013) of pantropical distribution and is considered to be the largest and most complex subfamily of Euphorbiaceae. It can be distinguished from others by the absence of milky latex, inarticulate laticiferous vessels (when present), simple or stellate indumentum, presence or absence of petals, and binucleate pollen grains that are mostly tricolpate or triporate. However, their pollen grains are also characterized as presenting 3–4 colpori, with a semitectate exine (Webster 1994). Palynological data can provide inferences of high taxonomic potential regarding the infra-familial classification in the Euphorbiaceae, a well-represented family in Caatinga ecoregion (Sampaio et al. 2002). However, there are few systematic studies addressing the supra-generic groups in this family. Thus, the present study aims to describe the pollen morphology of the representatives of Acalyphoideae and Euphorbioideae that occur in the Caatinga, with an emphasis on endemic taxa; to contribute to the palynological knowledge of these groups, and also to the pollen flora of Caatinga ecoregion. Materials and methods Flowers and/or flower buds from six species of Acalyphoideae and 18 species of Euphorbioideae were collected from dry specimens from the following herbaria: 123 UFP, HUEFS, HUNEB, PEUFR and HVASF (acronyms according to Thiers et al. 2015). All of the specimens examined are listed in the Appendix. Pollen grains were acetolysed following Erdtman (1960) and mounted on slides directly after being mixed with glycerine jelly and sealed with paraffin wax. Pollen grains were measured following the most important morphometric parameters: equatorial, polar and equatorial in a polar view diameter. Measurements were taken, whenever possible, using 25 pollen grains that were randomly chosen from three slides to achieve uniform sampling. The apertural and exine characters (apocolpium index, aperture dimensions, index polar area, and sexine and nexine thickness) were measured using ten pollen grains per specimen. For scanning electron microscope (SEM) analysis, all acetolysed pollen grains were washed and dehydrated in an ascending hydroacetonic series (50, 70, 90 and 100%) and remained in each series for 10 min. Absolute acetone with pollen grains was dropped directly over the SEM stubs, which were sputter coated by high vacuum gold evaporation. Pollen grains were analysed and photographed with LEO 1430 VP JSM and JEOL 6390LV microscopes. The pollen characteristics, such as size, shape, polarity, apertures, ornamentation, and exine sculpture, were visualized using optical and SEM photographs. Pollen descriptions followed the terminology by Punt et al. (2007) following the pollen size ranges defined by Erdtman (1952): medium, 25–50 lm; large, 50–100 lm; and very large, 100–200 lm. All pollen slides were deposited to the palynotheca collection of the Universidade Estadual de Feira de Santana (PUEFS). Results Acalyphoideae This subfamily showed variations in pollen characteristics, some of which presented a high diagnostic value, such as the aperture type and ornamentation of the exine (Figs. 1, 2, 8, 9, 10; Tables 1, 2). In general, the pollen grains are monads of medium to large size that were isopolar with varied forms ranging from suboblate to subprolate. They had a subcircular, circular and subtriangular amb, with a small, very small and large polar area; they were 3 (4)-colporate to 3-colpate and had an apertural membrane that is granulate (Fig. 1c) to echinate-granulate (Fig. 2j). The presence of an endocingulum and costa was restricted to the Dalechampia representatives (Fig. 1b, g, j), with a lalongate endoaperture and an exine that is microreticulate (Fig. 2h), reticulate (Fig. 1l), bireticulate (Fig. 2g) or microechinate-perforate (Fig. 2k). These pollen grains had a thicker sexine than a nexine. Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Fig. 1 Pollen grains of the species of Acalyphoideae of the Caatinga. Scale bars 10 lm. Dalechampia allemii: a optical section, polar view; b optical section, equatorial view; c detail of the aperture (SEM); d detail of the structure of the exine; e L.O. (high and low focus, resp.). Dalechampia peckoltiania: f optical section, equatorial view; g surface, equatorial view (SEM); h detail of the aperture (SEM). Dalechampia purpurata: i optical section, polar view; j optical section equatorial view; k surface, equatorial view (SEM); l detail of the surface (SEM) showing the free bacula in the lumen of the reticulum (arrow) 123 L. R. de Souza et al. Fig. 2 Pollen grains of species of Acalyphoideae of the Caatinga. Scale bars a–k = 10 lm; l = 5 lm. Ditaxis gardneri: a surface, polar view (SEM); b optical section equatorial view; c L.O. (high and low focus, resp.). Ditaxis malpighiaceae: d optical section polar view; 123 e optical section equatorial view; f surface; g detail of the surface (SEM); h L.O. (high and low focus, resp.). Omphalea brasiliensis: i surface, polar view (SEM); j surface, equatorial view; k detail of the surface (SEM); l detail of the structure of the exine (SEM) Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Table 1 Morphological characters of the pollen grains of species of Acalyphoideae and Euphorbioideae of the Caatinga Species Size Shape Polar area Amb Apertural type Exine S/N Dalechampia L. D. allemii G.L.Webster L SP-PS – Subcircular Reticulate, heterobrochate S[N D. peckoltiana Müll.Arg. L SP-PS – Subcircular Reticulate, heterobrochate S[N D. purpurata Cordeiro L SP – Subcircular 3-colporate, endocingulate 3-colporate, endocingulate 3-colporate, endocingulate Reticulate, heterobrochate S[N M SO Very small Subcircular 3-colporate S[N M SOOS Small Subcircular 3-colporate Microreticulate, heterobrochate Bireticulate, heterobrochate Euphorbia L. E. appariciana Rizzini M PS-SP Very small subcircular 3-colporate S[N E. chamaeclada Ule M SP Very small Subcircular 3-colporate E. heterodoxa Müll.Arg. M PS-SP Small Subcircular 3-colporate E. lycioides Boiss. M SP Very small Subcircular 3-colporate E. phosphorea Mart. M PS-SP Very small 3(4)-colporate E. sarcodes Boiss. E. tamanduana Boiss. M M PS-SP SP Very small Very small Subcircular to circular Subcircular Subcircular M PS Small subcircular 3-colporate microreticulate, heterobrochate Microreticulate, heterobrochate Microreticulate, heterobrochate Microreticulate, heterobrochate Microreticulate, heterobrochate Rugulate, heterobrochate microreticulate, heterobrochate Reticulate, heterobrochate M SP Very small Subcircular 3-colporate Microreticulate, heterobrochate S[N M PS subcircular M SP M PS Very small circular M. revoluta (Ule) Esser M PS-SP Very small circular 3(4)-colporate, sinuaperturate 3-colporate, sinuaperturate 3-colporate, sinuaperturate 3-colporate, sinuaperturate microreticulate-caveate, heterobrochate Microreticulate-caveate, heterobrochate Microreticulate, heterobrochate Microreticulate-caveate, homobrocada S[N M. marginata (Mart. & Zucc.) Klotzsch ex Müll.Arg. M. uleana (Pax & K.Hoffm.) Esser Without polar area Very small Omphalea L. O. brasiliensis Müll.Arg. M SO Very small Subtriangular 3-colpate microechinate-perforate, heterobrochate S[N Sapium P.Browne S. argutum Huber L P Small Subcircular 3-colporate Microreticulate, heterobrochate S[N Sebastiania Spreng. S. jacobinensis Müll.Arg. M PS-P Very small Subcircular 3-colporate S[N S. macrocarpa Müll.Arg. M SP Very small 3-colporate S SP – Circular to subcircular Subcircular Microreticulate-caveate, heterobrochate Microreticulate, heterobrochate Microreticulate L P Very small Circular 3-colporate Microreticulate, heterobrochate S[N Ditaxis Vahl ex A.Juss D. gardneri Pax & K.Hoffm. D. malpighiacea Pax & K.Hoffm. E. teres M.Machado & Hofacker Mabea Aubl. M. glaziovii Pax & K.Hoffm Microstachys A.Juss M. heterodoxa (Müll.Arg.) Esser S. larensis Croizat & Tamayo Stillingia L. S. trapezoidea Ule Subcircular 3-colporate 3-colporate 3-colporate S[N S[N S[N S[N S[N S[N S[N S[N S[N S[N S[N S[N – S small, M medium, L large, S spheroidal, PS prolate spheroidal, SP subprolate, P prolate, SO suboblate, OS oblate spheroidal 123 123 Table 2 Morphometric characters of the pollen grains of species studied of Acalyphoideae and Euphorbioideae of the Caatinga Specimens PD ED EDp x þ Sx Fv x þ Sx Fv x þ Sx Fv 54.6 ± 0.16 50.0–57.5 46.5 ± 0.11 45.0–50.0 47.7 ± 0.18 45.0–52.5 P/E Ecto PAI Sex Nex 1.17 27.5 9 1.5 – 3.0 1.3 Dalechampia D. allemii E. Melo 3192 et al. (HUEFS) E. Melo 5507 et al. (HUEFS) 51.4 ± 0.17 47.5–55.0 46.7 ± 0.18 42.5–52.5 45.5 ± 0.20 42.5–50.0 1.10 27.0–1.5 – 3.2 1.3 E. Melo 5513 et al. (HUEFS) 50.0 ± 0.15 45.0–50.0 46.1 ± 0.11 45.0–50.0 43.2 ± 0.09 42.5–45.0 1.06 23.0 9 1.4 – 3.0 1.0 C. Correia 63 et al. (HUEFS) L.V. Vasconcelos 74 (HUNEB) 77.4 ± 0.53 79.2 ± 0.77 70.0–85.0 70.0–105.0 90.0 ± 0.66 85.7 ± 0.77 75.0–102.5 60.0–100.0 63.0 ± 0.69 75.9 ± 0.91 52.5–82.5 50.0–100.0 1.16 1.08 31.1 9 1.2 – – 3.8 3.0 2.2 1.7 L.A. Sousa 204 (HUNEB) 56.4 ± 0.25 50.0–62.5 53.6 ± 0.34 47.5–60.0 47.9 ± 0.34 42.5–55.0 1.05 27.0 9 1.7 – 3.1 1.9 D. peckoltiana D. purpurata M.L. Guedes 8150 and E.Saar (HUEFS) 92.8 ± 0.26 87.5–100.0 76.1 ± 0.20 72.5–77.5 66.9 ± 0.21 62.5–72.5 1.21 38.9 9 2.0 – 5.2 1.9 A.A. Conceição 1927 et al. (HUEFS) 92.4 ± 0.16 87.5–95.0 70.9 ± 0.24 65.0–75.0 71.2 ± 0.25 67.5–75.0 1.30 38.3 9 2.3 – 5.5 1.9 1.1 Ditaxis D. gardneri D.N. Carvalho 147 (HUEFS) 36.0 ± 0.20 32.5–40.0 42.5 ± 0.14 37.5–45.0 38.2 ± 0.23 35.0–42.5 0.84 26.6 9 1.9 0.24 1.6 E. Melo 4319 et al. (HUEFS) 40.5 ± 0.17 37.5–42.5 45.7 ± 0.19 42.5–50.0 40.3a 37.5–45.0 0.88 – 0.24 1.0 1.0 R.F. Machado 337 (HUEFS) 32.5a 40.0a 37.5–42.5 39.1 ± 0.15 37.5–46.5 0.81 – 0.18 1.9 1.0 38.3 ± 0.17 35.0–42.5 37.5 ± 0.18 32.5–40.0 0.91 – 0.30 1.9 1.0 D. malpighiacea B. Stannard 51884 et al. (HUEFS) 34.9 ± 0.20 a 30.0–37.5 a R.M. Harley 54750 and R.M. Guilietti (HUEFS) 33.7 30.0–37.5 37.0 32.5–40.0 33.9 ± 0.20 30.0–37.5 0.91 – 0.25 1.3 0.9 J.R. Pirani 3729 et al. (HUEFS) 33.7 ± 0.22 30.0–37.5 42.4 ± 0.17 37.5–45.0 36.0 ± 0.18 30.0–37.5 0.79 – 0.15 1.6 1.0 29.5 ± 0.20 25.0–32.5 26.0 ± 0.11 25.0–30.0 26.2 ± 0.10 25.0–30.0 1.13 – 0.24 1.9 1.0 Euphorbia E. appariciana M.B.R. Caruzo 138 et al. (HUEFS) L.P. Queiroz 4277 et al. (HUEFS) 30.5 ± 0.21 27.5–32.5 24.4 ± 0.24 20.0–30.0 28.1 ± 0.16 25.0–32.5 1.25 – 0.19 1.3 0.9 F. França 5365 et al. (HUEFS) 33.3 ± 0.14 30.0–37.5 27.4 ± 0.07 25.0–30.0 31.2 ± 0.13 30.0–35.0 1.21 – 0.22 2.0 1.0 E. chamaeclada 26.4 ± 0.10 26.2–27.5 21.4 ± 0.10 20.0–22.5 22.2 ± 0.10 20.0–25.0 1.23 21.7 9 0.9 0.15 1.8 0.7 26.6 ± 0.15 25.0–30.0 20.4 ± 0.13 17.5–25.0 21.1 ± 0.11 17.5–22.5 1.30 – 0.15 2.0 0.9 L.P. Queiroz 5853 et al. (HUEFS) 36.2 ± 0.11 35.0–40.0 33.3 ± 0.13 30.0–35.0 35.5 ± 0.15 32.5–37.5 1.08 – 0.30 1.8 1.0 I. Cordeiro 2234 et al. (HUEFS) 40.4 ± 0.35 37.5–50.0 34.8 ± 0.24 30.0–42.5 37.5 ± 0.19 35.0–42.5 1.16 – 0.26 2.0 0.9 F. França 3145 et al. (HUEFS) 38.1 ± 0.18 35.0–42.5 35.6 ± 0.14 32.5–37.5 37.9 ± 0.12 35.0–40.0 1.07 – – 2.1 1.0 35.8 ± 0.20 32.5–40.0 29.0 ± 0.17 25.0–32.5 30.2 ± 0.18 25.0–32.5 1.23 – 0.22 2.0 1.0 – E. heterodoxa E. lycioides E. Melo 3640 et al. (HUEFS) L. R. de Souza et al. T.S. Nunes 537 (HUEFS) L.P. Queiroz 7888 et al. (HUEFS) Specimens PD ED EDp x þ Sx Fv x þ Sx Fv x þ Sx Fv 40.7 ± 0.18 37.5–45.0 35.5 ± 0.14 32.5–37.5 37.3 ± 0.08 35.0–37.5 P/E Ecto 1.14 – Sex Nex 0.21 2.0 1.0 – E. phosphorea E. Melo 4585 (HUEFS) PAI M.B.R. Caruzo 145 (HUEFS) 43.4 ± 0.22 40.0–47.5 34.1 ± 0.11 32.5–37.5 37.3 ± 0.14 35.0–40.0 1.27 – 0.23 2.3 1.0 F. França 1401 (HUEFS) F. França 1597 et al. (HUEFS) 38.7 ± 0.21 40.0a 35.0–42.5 37.5–42.5 33.8 ± 0.16 37.0a 30.0–37.5 35.0–37.5 37.1 ± 0.21 39.9 ± 0.19 32.5–42.5 37.5–45.0 1.14 1.08 – – 0.21 0.22 2.0 2.2 1.0 1.0 G.D. Alcântara 46 and A.M. Miranda (HUEFS) 43.6 ± 0.20 40.0–47.5 42.3 ± 0.12 40.0–47.5 42.5 ± 0.17 40.0–47.5 1.03 – 0.22 2.5 1.0 G. Almeida-Silva 103 and F.G. Moreira (HUEFS) 49.4 ± 0.19 45.0–55.0 41.1 ± 0.25 37.5–50.0 43.9 ± 0.10 42.5–45.0 1.20 – 0.18 2.5 1.1 E. Melo 4713 et al. (HUEFS) 46.0 ± 0.18 42.5–50.0 37.4 ± 0.09 35.0–40.0 41.5 ± 0.12 40.0–45.0 1.22 – 0.17 2.2 1.0 – E. sarcodes E. tamanduana M.B.R. Caruzo 147 et al. (HUEFS) 36.6 ± 0.11 32.5–37.5 28.9 ± 0.13 27.5–32.5 31.8 ± 0.16 27.5–35.0 1.26 – 0.14 2.1 1.0 M.B.R. Caruzo 136 et al. (HUEFS) 34.5 ± 0.23 27.5–37.5 27.8 ± 0.12 25.0–30.0 28.4 ± 0.18 25.0–32.5 1.24 – 0.16 2.7 0.9 L.P. Queiroz 5130 et al. (HUEFS) 34.4 ± 0.15 32.5–37.5 28.0 ± 0.16 25.0–32.5 29.2 ± 0.13 25.0–32.5 1.22 17.8 9 1.1 0.08 2.2 1.0 32.3 ± 0.14 30.0–35.0 30.2 ± 0.11 27.5–32.5 31.2 ± 0.13 27.5–35.0 1.06 – 0.33 1.9 1.1 36.7 ± 0.13 35.0–40.0 30.9 ± 0.15 27.5–35.9 30.6 ± 0.10 27.5–32.5 1.18 27.2 9 2.3 0.24 1.7 1.0 1.0 E. teres M. Machado 772 and A.K.A. Santos (HUEFS) Mabea M. glaziovii A.C Sarmento 828 M.P. Cardoso (HUEFS) Microstachys M. heterodoxa A.A Conceição 1198 (HUEFS) 31.8 ± 0.12 27.5–35.0 27.7 ± 0.15 25.0–30.0 27.8 ± 0.14 25.0–32.5 1.14 – 0.08 1.8 G. Almeida-Silva 184 and F.G. Moreira (HUEFS) 37.8 ± 0.15 35.0–42.5 35.1 ± 0.20 30.0–37.5 35.1 ± 0.20 32.5–37.5 1.07 – 0.07 2.7 0.9 L.P. Queiroz 9343 et al. (HUEFS) 27.5 ± 0.14 25.0–30.0 24.4 ± 0.14 22.5–27.5 25.2 ± 0.18 22.5–30.0 1.12 – 0.09 1.3 0.8 – M. marginata W. Ganev 3369 (HUEFS) 28.0 ± 0.11 25.0–30.0 23.6 ± 0.11 20.0–27.5 24.9 ± 0.14 22.5–27.5 1.18 – 0.18 1.3 1.0 W. Ganev 2103 (HUEFS) 29.1 ± 0.11 27.5–30.0 23.6 ± 0.14 22.5–27.5 24.6 ± 0.13 22.5–27.5 1.23 – 0.14 1.6 0.9 W. Ganev 342 (HUEFS) 28.3 ± 0.09 27.5–30.0 25.7 ± 0.09 25.0–27.5 25.2 ± 0.14 22.5–27.5 1.10 – 0.08 1.9 1.0 0.14 2.2 1.0 – M. revoluta E.L. Barbosa 1819 et al. (HUEFS) 35.4 ± 0.18 30.0–37.5 29.8 ± 0.14 27.5–32.5 31.0 ± 0.12 27.5–32.5 1.18 – 123 J.G. Nascimento 292 et al. (HUEFS) 33.7 ± 0.14 32.5–37.5 30.6 ± 0.18 27.5–35.0 29.6 ± 0.13 27.5–32.5 1.10 – – 2.5 1.0 R.M. Harley 54497 and A.M. Giulietti (HUEFS) 31.9 ± 0.17 27.5–35.0 28.7 ± 0.11 25.0–30.0 30.7 ± 0.16 27.5–32.5 1.11 – – 1.1 0.9 28.3 ± 0.09 27.5–30.0 25.5 ± 0.11 22.5–27.5 26.1a 22.5–27.5 1.10 0.20 1.7 1.0 – M. uleana M. Alves 1238 et al. (UFP) – Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Table 2 continued 123 Table 2 continued Specimens PD ED EDp P/E Ecto PAI Sex Nex x þ Sx Fv x þ Sx Fv x þ Sx Fv 29.3a 27.5–32.5 36.8a 35.0–40.0 34.6 ± 0.16 32.5–37.5 0.79 – 0.21 1.0 0.6 A.M. Miranda 3632 (HUEFS) 52.6 ± 0.18 38.8 ± 0.13 38.3a 50.0–60.0 37.5–42.5 37.5–40.0 1.35 46.3 9 1.4 0.28 2.0 1.0 A.M. Miranda 3647 (HUEFS) 50.8 ± 0.18 47.5–55.0 37.2 ± 0.14 35.0–42.5 35.0a 35.0–35.0 1.36 40.7 9 1.7 – 2.2 1.0 Omphalea O. brasiliensis E.M.N. Ferraz 712 (PEUFR) Sapium S. argutum Sebastiania S. jacobinensis E. Mello 4629 et al. (HUEFS) 27.3 ± 0.12 25.0–30.0 24.6 ± 0.09 22.5–27.5 24.8 ± 0.14 22.5–27.5 1.10 – 0.22 1.4 1.0 Grupo Pedra do Cavalo 737 (HUEFS) 37.0 ± 0.16 35.0–40.0 26.5 ± 0.11 25.0–30.0 27.2 ± 0.12 25.0–30.0 1.39 – 0.19 1.8 1.0 A.G. Silva 361 and L.M. Nascimento (HUEFS) 35.5 ± 0.15 32.5–37.5 28.9 ± 0.10 27.5–30.0 30.3 ± 0.13 27.5–32.5 1.22 27.1 9 1.7 0.25 1.5 1.0 15.9 ± 0.11 12.5–17.5 13.2 ± 0.10 10.0–15.0 14.3 ± 0.09 12.5–15.0 1.20 – – – – S. larensis J.A. Siqueira-Filho 2579 et al. (HVASF) – S. macrocarpa M. Oliveira 4594 et al. (HVASF) 37.4 ± 0.14 35.0–42.5 30.6 ± 0.11 30.0–35.0 31.0 ± 0.16 30.0–37.5 1.22 – 0.18 1.5 1.0 A.C.P. Oliveira 3246 et al. (HVASF) 38.2 ± 0.10 37.5–40.0 29.5 ± 0.14 27.5–32.5 32.6 ± 0.13 30.0–35.0 1.29 – 0.19 2.0 1.0 37.9 ± 0.16 35.0–42.5 30.2 ± 0.12 27.5–35.0 33.6 ± 0.21 30.0–37.5 1.25 – 0.20 2.0 1.0 F. França 2430 et al. (HUEFS) 54.1 ± 0.27 45.0–60.0 36.2 ± 0.15 32.5–40.0 38.1a 37.5–40.0 1.49 48.8 9 1.5 0.11 1.6 1.0 A. Rapini 1342 and R. Souza-Silva (HUEFS) 50.0 ± 0.19 47.5–55.0 34.9 ± 0.14 32.5–37.5 37.5a 37.5–37.5 1.43 45.9 9 1.8 0.16 1.2 1.0 M.C. Pessoa 81 and J.R. Lima (HUEFS) 57.6 ± 0.15 50.0–60.0 37.2 ± 0.12 35.0–40.0 – – 1.54 – – 2.3 1.0 V.M. Catorelli 1116 et al. (HVASF) Stillingia S. trapezoidea PD polar diameter, ED equatorial diameter, EDp equatorial diameter in polar view, P/E polar diameter/equatorial diameter, Ecto length 9 width of the ectoaperture, PAI polar area index, Sex sexine, Nex nexine a n \ 25 measurements for pollen grain diameter; measurements in lm and indices in absolute numbers L. R. de Souza et al. Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Based on the ornamentation of the exine, it was possible to establish four pollen types that conferred well-marked characteristics on each analysed genus. The only exception was for the species of Ditaxis that presented two patterns of exine ornamentation (Fig. 2a, g, j, k; Tables 1, 2). Type 1: Reticulate pollen grains Species: Dalechampia allemii G.L.Webster, Dalechampia peckoltiana Müll.Arg., and Dalechampia purpurata Cordeiro (Fig. 1). Large pollen grains, prolate spheroidal to subprolate (D. purpurata), subcircular amb, 3-colporate, narrow and short ectoaperture with rounded extremities (Fig. 1c, k), endoaperture in the endocingulum, presence of costa and fastigium (Fig. 1b, f, j). Reticulate exine, heterobrochate, simplicolumellate with smaller lumina at the apertures (Fig. 1k), free bacula in the lumen of the reticulum (in D. purpurata, Fig. 1l); sinuous, smooth, high and continuous muri. Sexine thicker than nexine. Euphorbioideae In this group, the pollen characteristics demonstrated variability in size, shape, amb, and polar area. The ornamentation of the exine and presence or absence of the margo consisted of features that had great value for the palynological separation of taxa, especially when associated with the size of the pollen grains (Figs. 3, 4, 5, 6, 7, 8, 9, 10; Tables 1, 2). The pollen grains can be described as small to large and prolate spheroidal to prolate, with a subcircular to circular amb, very small to small polar area, 3-(4)-colporate with psilate (Fig. 5f) or a microreticulate margo (Fig. 7k); granulate apertural membrane and lalongate to lolongate endoaperture, with an exine that is microreticulate (Fig. 5i), microreticulate-rugulate (Fig. 4e, f), or microreticulate-caveate (Fig. 5g) to reticulate (Fig. 7k, l). The sexine is thicker than the nexine. Type 1: Pollen grains with psilate margines Species: Ditaxis gardneri Pax & K.Hoffm. (Fig. 2a–c). Medium pollen grains, suboblate, isopolar, subcircular amb, very small polar area, 3-colporate. Narrow, very long, with slightly rounded extremities of the ectoaperture, and a lalongate endoaperture. Microreticulate exine, with smaller lumina in the apocolpium; sinuous, smooth and continuous muri. Sexine thicker than nexine. The species belonging to this group are those with small, medium, and large pollen grains that are isopolar; the species are prolate spheroidal to prolate without a polar area (IAP = 0.08; Table 2); a very small polar area, subcircular to circular amb; 3(4)-colporate and granulate apertural membrane; lalongate endoaperture; exine that is microreticulate, microreticulate-rugulate, or microreticulate-caveate to finely microreticulate; and have a sexine thicker than the nexine. Type 3: Bireticulate pollen grains Subtype 1.1: Small pollen grains Species: Ditaxis malpighiacea Pax & K.Hoffm. (Fig. 2d– h). Medium pollen grains, suboblate to oblate spheroidal, isopolar, subcircular amb, small polar area, 3-colporate. Narrow and long ectoaperture, lalongate endoaperture difficult to see. Bireticulate exine, heterobrochate, sinuous, smooth and continuous muri. Sexine thicker than nexine. Species: Sebastiania larensis Croizat & Tamayo (Fig. 3a, b). Small pollen grains, subprolate, subcircular amb, 3-colporate, narrow ectoaperture, microreticulate exine. Type 4: Microechinate-perforate pollen grains Species: Euphorbia appariciana Rizzini, E. heterodoxa Müll.Arg., E. lycioides Boiss., E. phosphorea Mart., E. sarcodes Boiss., E. tamanduana Boiss., Mabea glaziovii Pax & K.Hoffm., Microstachys heterodoxa (Müll.Arg.) Esser, M. marginata (Mart. & Zucc.) Klotzsch ex Müll.Arg., M. revoluta (Ule) Esser, M. uleana (Pax & K.Hoffm.) Esser, Sebastiania jacobinensis Müll.Arg., S. macrocarpa Müll.Arg. (Figs. 3 c–l, 4a–g, 5a–g, 6a–g). Type 2: Microreticulate pollen grains Species: Omphalea brasiliensis Müll.Arg. (Fig. 2i–l). Medium pollen grains, suboblate, isopolar, subtriangular amb, very small polar area, 3-colporate. Very long ectoapertures, generally difficult to see under LM, with a microechinate apertural membrane. Microechinate-perforate exine. Sexine thicker than nexine. Subtype 1.2: Medium pollen grains 123 L. R. de Souza et al. Fig. 3 Pollen grains of species of Euphorbioideae of the Caatinga. Scale bars 10 lm. Sebastiania larensis: a optical section polar view; b surface, equatorial view (SEM). Euphorbia appariciana: c optical section polar view, note margo; d surface, equatorial view (SEM); e detail of the surface. Euphorbia heterodoxa: f optical section 123 equatorial view; g detail of the aperture; h optical section polar view; i detail of the surface. Euphorbia lycioides: j surface, polar view (SEM); k surface, equatorial view (SEM); l detail of the structure of the exine (SEM) Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Fig. 4 Pollen grains of species of Euphorbioideae of the Caatinga. Scale bars 10 lm. Euphorbia phosphorea: a optical section polar view; b surface, polar view (SEM); c surface, equatorial view (SEM). Euphorbia sarcodes: d optical section polar view; e surface, equatorial view (SEM); f L.O. (high and low focus, resp.) Euphorbia tamanduana: g optical section polar view; h detail of the aperture, showing the margo; i detail of the surface. Mabea glaziovii: j surface, polar view (SEM); k surface, equatorial view (SEM); l detail of the surface (SEM) 123 L. R. de Souza et al. Fig. 5 Pollen grains of species of Euphorbioideae of the Caatinga. Scale bars a–e, g–l = 10 lm; f = 5 lm. Microstachys heterodoxa: a optical section polar view; b surface, equatorial view (SEM); c detail of the surface (SEM). Microstachys marginata: d optical section polar view; e surface, equatorial view (SEM); f surface, 123 showing the aperture. Microstachys revoluta: g optical section polar view; h surface, equatorial view (SEM); i detail of the surface. Microstachys uleana: j optical section polar view; k surface, equatorial view (SEM); l L.O. (high and low focus, resp.) Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Fig. 6 Pollen grains of species of and Euphorbioideae of the Caatinga. Scale bars 10 lm. Sebastiania jacobienensis: a surface, polar view (SEM); b surface, equatorial view (SEM); c optical section equatorial view; d L.O. (high and low focus, resp.). Sebastiania macrocarpa: e surface, polar view (SEM); f surface, equatorial view (SEM); g L.O. (high and low focus, resp.). Sapium argutum: h optical section polar view; i optical section equatorial view; j detail of the margo (SEM); k detail of the aperture; l L.O. (high and low focus, resp.) 123 L. R. de Souza et al. Fig. 7 Pollen grains of species of Euphorbioideae of the Caatinga. Scale bars 10 lm. Stilingia trapezoidea: a optical section polar view; b optical section equatorial view; c surface, equatorial view (SEM); d detail of the aperture (SEM). Euphorbia chamaeclada: e optical section polar view; f optical section equatorial view; g surface, 123 equatorial view (SEM); h detail of the structure of the exine (SEM). Euphorbia teres: i surface, polar view (SEM); j optical section equatorial view; k detail of the aperture (SEM); l L.O. (high and low focus, resp.) Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Fig. 8 Boxplot graph of the distribution of variable polar diameter of the pollen grains. The horizontal bar inside the rectangle is the median, the rectangle shows 50% of interquartile, ends show the amplitude variation, and the asterisks correspond to the outlier Fig. 9 Boxplot graph of the distribution of variable equatorial diameter of the pollen grains. The horizontal bar inside the rectangle is the median, the rectangle shows 50% of interquartile, ends show the amplitude variation, and the asterisks correspond to the outlier Medium pollen grains, subprolate to prolate, subcircular to circular amb, no polar area (IAP = 0.08; Table 2) (M. heterodoxa), small to very small polar area (E. heterodoxa), 3-colporate to 3(4)-colporate (E. phosphorea and M. heterodoxa), sinu-aperture (M. hetorodoxa, M. marginata, M. uleana, and M. revoluta), sometimes syncolporate (S. macrocarpa) (Fig. 6e), very long and narrow ectoaperture (except in M. heterodoxa), rounded extremities (E. sarcodes and S. jacobinensis), fused to rounded extremities (Euphorbia appariciana, E. phosphorea, and S. macrocarpa), or fused extremities. Microreticulate-rugulate exine (E. sacordes, Fig. 4e); microreticulate-homobrochatecaveate (M. heterodoxa, M. marginata, M. revoluta, and S. jacobinensis) (Fig. 5i) to microreticulate heterobrochate (Fig. 5l) in the other species. Subtype 1.3: Large pollen grains Species: Sapium argutum Huber and Stillingia trapezoidea Ule (Figs. 6h–l, 7a–d). Large pollen grains, prolate, subcircular to circular amb, very small to small polar area (Stillingia trapezoidea), narrow 3-colporate and long to very long ectoaperture (S. trapezoidea, Fig. 7b), fused and slightly rounded extremities (S. trapezoidea), and an endoaperture with parallel and arched margines (Sapium argutum, Fig. 6k). 123 L. R. de Souza et al. Fig. 10 Boxplot graph of the distribution of variable equatorial diameter in polar view of the pollen grains. The horizontal bar inside the rectangle is the median, the rectangle shows 50% of interquartile, ends show the amplitude variation, and the asterisks correspond to the outlier Microreticulate-heterobrochate exine, with smaller lumina in the apertural region (S. trapezoidea). Type 2: Pollen grains with microreticulate margines Species: Euphorbia chamaeclada Ule and E. teres M.Machado & Hofacker (Fig. 7e–l). Medium pollen grains, subprolate to prolate spheroidal (E. teres), subcircular amb, very small to small polar area (E. teres), 3-colporate, long to very long ectoaperture (E. chamaeclada), narrow, with rounded extremities (E. teres), apertural rugulate membrane (E. teres) (Fig. 7j–k), and lalongate to lolongate (Fig. 7j) endoaperture (E. teres). Microreticulate (Fig. 7g) to reticulate exine (E. teres, Fig. 7l), heterobrochate, sinuous, smooth and continuous muri. Discussion Acalyphoideae The ornamentation of the exine consisted of a feature that had a great distinguishing value between the genera that were analysed, confirming the ‘‘taxonomic-palynological’’ connection that Erdtman (1969) had established for the delimitation of the Euphorbiaceae family representatives. An exception was observed in the genus Ditaxis, whose species (which were studied under SEM) showed distinct palynological patterns with a bireticulate exine in D. malpighiacea and microreticulate exine in D. gardneri. Punt (1962), when describing the pollen grains of the genus, found a psilate exine, while Zavaleta and Palacios- 123 Chavez (1980) observed reticulate pollen grains and Takahashi et al. (1995) and Nowicke et al. (1999) described a perforate surface. Endocingulate pollen grains, with costa and a reticulate exine, are particular to the Dalechampia genus; this was already observed by Zavaleta and Palacios-Chavez (1980), Punt (1962), Roubik and Moreno (1991), Nowicke and Takahashi (2002), Cruz-Barros et al. (2006) and Corrêa et al. (2010). The lumina of the reticle are smaller near the apertures, which was observed in this study; this was also corroborated by the above-mentioned authors, except for Punt (1962) and Corrêa et al. (2010). The presence of bacula inside the lumina of the reticulum, as observed in D. purpurata, has not yet been recorded in the literature. Regarding the pollen grains of Omphalea, Roubik and Moreno (1991), when studying Omphalea diandra L, described them as scabrate, while Carreira et al. (1991) described them as granulate under LM and microechinate under SEM. The description provided by the aforementioned authors is close to that found in this study. Omphalea presented an apertural type that is not particular to the Euphorbioideae, the colpate; furthermore, the ornamentation of the exine of its pollen grains (microechinateperforate) differed from the patterns presented by the taxa of the Acalyphoideae subfamily. Echinate or microechinate pollen grains are uncommon in the family of Euphorbiaceae (Nowicke et al. 1998). The phylogenetic position of this genus was uncertain among the Acalyphoideae, leading Wurdack et al. (2005) to suggest its exclusion from the Acalyphoideae and inclusion into Crotonoideae in the Adenoclineae tribe (3-colpate pollen grains). Even not related, Omphalea Cheilosoideae subfamily share pollen grains with an echinate exine. Pollen morphology of the Acalyphoideae and Euphorbioideae (Euphorbiaceae) of the Caatinga Euphorbioideae The aperturate colporate type consisted of a pattern of pollen characteristics to the subfamily, occurring in all of the species that were investigated and varying only in aperture number (3–4). Pollen grains that are 4-colporate are less frequent; here, they were only observed in Euphorbia phosphorea and Microstachys heterodoxa, yet 3-colporate pollen grains were present in a greater proportion in the analysed specimens. The type of margo ornamentation and size of the pollen grains were features that allowed the palynological segregation of the studied species. The presence of a margo was a pollen characteristic of wide occurrence in the Euphorbioideae subfamily that was present in all of the analysed species. The presence of a margo is a very well-recorded feature in the palynological literature of Euphorbioideae. In general, the margo ranged from psilate to microreticulate, the latter being restricted to only two species of Euphorbia (E. chamaeclada and E. teres); this condition is cited here for the first time. There have been reports of a psilate margo (Carneiro-Torres et al. 2002), granulate (El-Ghazaly and Chaudhary 1993; Chaudhary and El-Ghazaly 1994) and perforate margo (El-Ghazaly and Chaudhary 1993) for species of Euphorbia. The presence of a psilate margo was observed in species of the Mabea, Sapium, Sebastiania, and Stillingia. This condition was presented in the study of Cruz-Barros et al. (2006) for one species of the genera Sebastiania. For species of the Mabea, Sapium, and Stillingia the character is reported for the first time. The Euphorbia species have granulate apertural membrane (El-Chazaly 1989; El-Ghazaly and Chaudhary 1993; Chaudhary and El-Ghazaly 1994; Park 1997, 1998) and psilate (Palacios-Chávez et al. 1991; El-Ghazaly and Chaudhary 1993). A granulate and rugulate membrane was verified in the present study, the latter being restricted to Euphorbia teres. According to Lynch and Webster (1975), from the palynological point of view, Euphorbia is more related to Stillingia because both have marginate colpi. However, the present study showed that a margo was found in all of the genera that were analysed (Euphorbia, Mabea, Microstachys, Sapium, Sebastiana, and Stillingia). Only the ornamentation varied. However, the presence of this feature was not restricted to only one group. Thus, it was not used in the pollen-type segregation. The endoaperture presented itself predominantly as the lalongate type. However, it appeared lolongate only in Euphorbia teres. El-Ghazaly and Chaudhary (1993), Chaudhary and El-Ghazaly (1994), Cruz-Barros et al. (2006) and Corrêa et al. (2010), when studying the Euphorbia species, observed pollen grains with lalongate and lolongate endoapertures. Thus, the variation observed in this study was expected with regard to this feature. The ornamentation of the exine in the Euphorbioideae subfamily was shown to vary between microreticulate, microreticulate-rugulate, microreticulate-caveate, and reticulate. In general, the exine for the representatives of Euphorbioideae presents as psilate (Punt 1962), pilate (Gonçalves-Esteves et al. 1986), baculate (Roubik and Moreno 1991), rugulate, fossulate, reticulate (El-Ghazaly and Chaudhary 1993) microreticulate, perforate (CarneiroTorres et al. 2002), microreticulate-caveate (Cruz-Barros et al. 2006), and reticulate-cristate (Corrêa et al. 2010). Therefore, in terms of this feature, the data presented here are in accordance with those encountered in the literature. The ornamentation of the Euphorbioideae pollen grains is a feature of high taxonomic value. Webster (1994) and Radcliffe-Smith (2001) used palynological data (surface of the exine) to separate the tribes belonging to this subfamily. Thus, the representatives of the Stomatocalyceae tribe were characterized by reticulate pollen grains and those of the Euphorbieae tribes (Euphorbia), Hureae, Hippomaneae (Mabea, Microstachys, Sapium Sebastiania, and Stillingia) and Pachystromateae had perforate pollen grains. In the specimens that were investigated here, the ornamentation of the reticulate exine was verified in the representatives of the Euphorbieae and Hippomaneae tribes, thereby demonstrating that this pattern of exine is not only restricted to Stomatocalyceae. Conclusions The high variability in pollen morphology observed between the specimens that were analysed enabled us to confirm the eurypalynous feature of Euphorbiaceae because variations were observed in the size, shape, polar area, amb, number and apertural type, and exine ornamentation. In Acalyphoideae, the pollen characteristics were more diverse; one exine ornamentation pattern was shown for each genus that was analysed, and there was also variation between species of the same genus, as noted in Ditaxis. Furthermore, there was variation in the apertural type, being colpate in Omphalea brasiliensis and colporate in the other species. Euphorbioideae, in turn, had representatives that were characterized by pollen grains with a margo in the apertures (colpori). In general, there was variation in the patterns of reticula of the pollen grain sexine. This study allowed us to register new pollen features, such as the presence of a psilate margo in Mabea, Sapium, and Stillingia species, for which the specialized literature 123 L. R. de Souza et al. did not describe such a characteristic by pollen literature analysed. The study was also able to expand palynological knowledge of the groups that were studied. Acknowledgements The authors thank the Coordenadoria de Aperfeiçoamento de Pessoal de Nı́vel Superior (CAPES) for the fellowship granted to the first author; Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico (CNPq) for supporting the senior author (#303862/2013-0); and the curators and staff of UFP, HUEFS, HUNEB, PEUFR and HVASF. The authors also thank The Fundação Instituto Osvaldo Cruz (FIOCRUZ)—Centro de pesquisa Gonçalo Moniz, for SEM facilities; and Laboratório de Palinologia da Universidade do Estado da Bahia (Campus VII) laboratory facilities with light microscopy. Authors also thank three anonymous reviewers for their constructive comments. Compliance with ethical standards Conflicts of interest Author Lidian Ribeiro de Souza has received research grant from Coordenação de Aperfeiçoamento de Pessoal de Nı́vel Superior (BR). Author Francisco de Assis Ribeiro dos Santos has received research grant from Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico (BR) (#303862/2013-0, 405636/2013-0). Ethical statement This study was conducted following the accepted principles of ethics and professional conduct. Appendix Specimens investigated. Dalechampia allemii G.L.Webster. Brazil: Bahia, Morro do Chapéu, 18 Nov 1999, E. Melo 3192 (HUEFS); Bahia, Morro do Chapéu, 17 Apr 2008, E. Melo 5507 (HUEFS); Bahia, Morro do Chapéu, 17 Apr 2008, E. Melo 5513 (HUEFS). Dalechampia peckoltiana Müll.Arg. Brazil: Bahia, Caetité, 29 Apr 2001, C. Correia 63 (HUEFS); Bahia, Caetité, 29 Apr 2001, C. Correia et al. 63 (HUEFS); Bahia, Caetité, 29 Apr 2008, L.V. Vasconcelos 74 (HUNEB). Dalechampia purpurata Cordeiro. Brazil: Bahia, Barra do Mendes, 24 Jan 2001, M.L.S. Guedes 8150 (HUEFS); Bahia, Paramirim, 28 Apr 2007, A.A. Conceição 1927 (HUEFS). Ditaxis gardneri Pax & K.Hoffm. Brazil: Bahia, Conceição do Coité, 11 Nov 2012, D.N. Carvalho 147 (HUEFS); Bahia, Itaberaba, 19 Mar 2006, E. Melo 4319 (HUEFS); Bahia, Morro do Chapéu, 31 Oct 2009, R.F. Machado 337 (HUEFS). Ditaxis malpighiacea Pax & K.Hoffm. Brazil: Bahia, Abaı́ra, 12 Mar 1992, B. Stannard 51884 (HUEFS); Bahia, Rio de Contas, 2 Feb 2004, R.M. Harley 54750 (HUEFS); Minas Gerais, Santo Hipólito, 3 Apr 1996, J.R. Pirani 3729 (HUEFS). Euphorbia appariciana Rizzini. Brazil: Bahia, Morro do Chapéu, 14 Mar 1995, L.P. Queiroz 4277 (HUEFS); Bahia, 123 Morro do Chapéu, 17 Dec 2005, F. França 5365 (HUEFS); Bahia, Morro do Chapéu, 10 Feb 2009, M.B.R. Caruzo 138 (HUEFS). Euphorbia chamaeclada Ule. Brazil: Bahia, Casa Nova, 16 Jun 2001, T.S. Nunes 537 (HUEFS); Bahia, Casa Nova, 5 Jul 2003, L.P. Queiroz 7888 (HUEFS). Euphorbia heterodoxa Müll.Arg. Brazil: Bahia, Bom Jesus da Lapa, 11 Feb 2000, L.P. Queiroz 5853 (HUEFS); Bahia, Jacobina, 25 Jun 1999, F. França 3145 (HUEFS); Bahia, Morro do Chapéu, 9 Apr 2000, I. Cordeiro 2234 (HUEFS). Euphorbia lycioides Boiss. Brazil: Bahia, Palmeiras, 28 Mar 2003, E. Melo 3640 (HUEFS). Euphorbia phosphorea Mart. Brazil: Bahia, Itatim, 14 Oct 1995, F. França 1401 (HUEFS); Bahia, Itatim, 20 Apr 1996, F. França 1597 (HUEFS); Bahia, Morro do Chapéu, 14 Oct 2006, E. Melo 4585 (HUEFS); Bahia, Morro do Chapéu, 10 Feb 2009, M.B.R. Caruzo 145 (HUEFS). Euphorbia sarcodes Boiss. Brazil: Bahia, Morro do Chapéu, 14 Apr 2007, E. Melo 4713 (HUEFS); Bahia, Palmeiras, 12 Jan 2012, G. Almeida-Silva 103 (HUEFS); Pernambuco, Buı́que, 14 Feb 2008, G.D. Alcântara 46 (HUEFS). Euphorbia tamanduana Boiss. Brazil: Bahia, Morro do Chapéu, 11 Feb 2009, M.B.R. Caruzo 147 (HUEFS); Bahia, Morro do Chapéu, 10 Feb 2009, M.B.R. Caruzo 136 (HUEFS); Bahia, Umburanas, 9 Apr 1999, L.P. Queiroz 5130 (HUEFS). Euphorbia teres M.Machado & Hofacker. Brazil: Bahia, Seabra, 4 Feb 2006, M. Machado 772 (HUEFS). Mabea glaziovii Pax & K.Hoffm. Brazil: Bahia, Morro do Chapéu, 31 Mar 1986, A.C. Sarmento 828 (HUEFS). Microstachys heterodoxa (Müll.Arg.) Esser. Brazil: Bahia, Boqueirão, 5 Mar 2005, A.A. Conceição 1198 (HUEFS); Bahia, Palmeiras, 13 Mar 2012, G. AlmeidaSilva 184 (HUEFS); Bahia, Rui Barbosa, 28 Jul 2004, L.P. Queiroz 9343 (HUEFS). Microstachys marginata (Mart. & Zucc.) Klotzsch ex Müll.Arg. Brazil: Bahia, Abaı́ra, 14 Jun 1994, W. Ganev 3369 (HUEFS); Bahia, Rio de Contas, 25 Jul 1993, W. Ganev 2109 (HUEFS); Bahia, Abaı́ra, 22 May 1992, W. Ganev 342 (HUEFS). Microstachys revoluta (Ule) Esser. Brazil: Bahia, Mucugê, 4 Aug 2004, E.L. Borba 1819 (HUEFS); Bahia, Mucugê, 21 Jan 2005, J.G.A. Nascimento 292 (HUEFS); Bahia, Mucugê, 15 Feb 2002, R.M. Harley 54497 (HUEFS). Microstachys uleana (Pax & K.Hoffm.) Esser. 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