Abstract
Taxonomic studies on the genus Croton in the Midwest region of Brazil enabled the analysis of about 700 collections from all over the country. Three of these collections were identified as a new species, Croton piriquetifolius, which is described and illustrated here. We also give a preliminary evaluation of its conservation status, provide data on flowering and fruiting seasons, geographic distribution environmental preferences, as well as its systematic position. The new species is compared macro- and micromorphologically with C. adamantinus, C. glandulosus and C. eremophilus, with which it resembles or has been confused in herbaria. Morphological (e.g., presence, shape, and location of the acropetiolar nectaries, presence, and distribution of glands on stipules, presence, and size of pedicel on pistillate flower, integrity of styles, type, and location of trichomes) and anatomical (e.g., disposition of the stomata, contour of petiole and midrib, organization of vascular bundles, type of mesophyll, and types of trichomes) characters serve to differentiate the species studied.
References
- Aublet, J.B.C.F. (1775) Histoire des plantes de la Guiane Françoise 1. Pierre-François Didot, London & Paris, 621 pp.
- Bachman, S., Moat, J., Hill, A.W., Torre, J. & Scott, B. (2011) Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. ZooKeys 150: 117–126. https://doi.org/10.3897/zookeys.150.2109
- Baillon, H.E. (1858) Étude générale du groupe des Euphorbiacées. Librairie de Victor Masson, Paris, 684 pp. https://doi.org/10.5962/bhl.title.50439
- Baillon, H.E. (1864) Species Euphorbiacearum. Euphorbiacées Américaines. Première partie: Amérique austro-orientale. Adansonia 4: 257–377.
- Barbosa, B.L.R., Oliveira, R.P., Mascarenhas, A.A.S., Dórea, M.C., Martins, F.M. & Carneiro-Torres, D.S. (2018) Croton aemulus and C. graomogolensis (Euphorbiaceae): Two new species from Minas Gerais, Brazil, based on distinct lines of evidence and their relation to C. muscicapa and C. longibracteatus. Phytotaxa 365 (3): 259–272. https://doi.org/10.11646/phytotaxa.365.3.4
- Barros, I.O. & Soares, A.A. (2013) Adaptações anatômicas em folhas de marmeleiro e velame da Caatinga brasileira. Revista Ciência Agronômica 44: 192–198. https://doi.org/10.1590/S1806-66902013000100024
- Bieras, A.C. & Sajo, M.G. (2009) Leaf structure of the cerrado (Brazilian savanna) woody plants. Trees 23: 451–471. https://doi.org/10.1007/s00468-008-0295-7
- Bukatsch, F. (1972) Bemerkungen zur Doppelfärbung Astrablau-Safranin. Mikrokosmos 61: 255.
- Burchell, W.J. (1824) Travels in the interior of Southern Africa 2. Longman, Hurst, Rees, Orme & Brown, London, 648 pp. https://doi.org/10.5962/bhl.title.109918
- Carneiro-Torres, D.S. (2009) Diversidade de Croton L. (Euphorbiaceae) no Bioma Caatinga. Doctoral Thesis. Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, 296 pp.
- Caruzo, M.B.R., Secco, R.S., Medeiros, D., Riina, R., Torres, D.S.C., Santos, R.F.D., Pereira, A.P.N., Rossine, Y., Lima, L.R., Muniz Filho, E. & Valduga, E. (2020) Croton. In: Flora e Funga do Brasil 2020. Jardim Botânico do Rio de Janeiro. Available from: https://floradobrasil.jbrj.gov.br/FB17497 (accessed 25 October 2023)
- Carvalho, C.R.V., Soares, E.K.S. & Oliveira, A.B. (2019) Morfoanatomia foliar de Copaifera sabulicola J.A.S. Costa & L.P. Queiroz: uma planta com potencial medicinal. Hoehnea 46: e192018. https://doi.org/10.1590/2236-8906-19/2018
- Castro, E.M., Pereira, F.J. & Paiva, R. (2009) Histologia Vegetal: Estrutura e função de órgãos vegetativos. UFLA, Lavras, Minas Gerais, 234 pp.
- Cen, Y. & Bornman, J.F. (1993) The effect of exposure to enhanced UV-B radiation on the penetration of monochromatic and polychromatic UV-B radiation in leaves of Brassica napus. Physiologia Plantarum 87: 249–255. https://doi.org/10.1111/j.1399-3054.1993.tb01727.x
- De Lucia, E.H., Nelson, K., Vogelmann, T.C. & Smith, W.K. (1996) Contribution of the intercellular reflectance to photosynthesis in shade leaves. Plant, Cell & Enviroment 19: 159–170. https://doi.org/10.1111/j.1365-3040.1996.tb00237.x
- Dickison, W.C. (2000) Integrative plant anatomy. Academic Press, San Diego, 533 pp.
- Dmitruk, M., Sulborska, A., Żuraw, B., Stawiarz, E. & Weryszko-Chmielewska, E. (2019) Sites of secretion of bioactive compounds in leaves of Dracocephalum moldavica L.: anatomical, histochemical, and essential oil study. Brazilian Journal of Botany 42: 701–715. https://doi.org/10.1007/s40415-019-00559-6
- Evert, R.F. (2006) Esau’s plant anatomy: meristems, cells and tissues of the plant body: their structure, function and development. 3rd ed. Wiley & Sons, New Jersey, 601 pp. https://doi.org/10.1002/0470047380
- Fahn, A. (1979) Secretory tissues in plants. Academic Press, London, 312 pp.
- Fahn, A. (1986) Structural and functional properties of trichomes of xeromorphic leaves. Annals of Botany 57: 631–637. https://doi.org/10.1093/oxfordjournals.aob.a087146
- Fahn, A. & Cutler, D.F. (1992) Xerophytes. Gebrüder Borntraeger, Berlin, 176 pp.
- Feio, A.C., Meira, R.M.S.A. & Riina, R. (2018) Leaf anatomical features and their implications for the systematics of dragon’s blood, Croton section Cyclostigma (Euphorbiaceae). Botanical Journal of the Linnean Society 187: 614–632. https://doi.org/10.1093/botlinnean/boy038
- Freitas, L., Bernardello, G., Galetto, L. & Paoli, A.A.S. (2001) Nectaries and reproductive biology of Croton sarcopetalus (Euphorbiaceae). Botanical Journal of the Linnean Society 136: 267–277. https://doi.org/10.1111/j.1095-8339.2001.tb00572.x
- Gancedo, N.C., Lima, C.B., Milaneze-Gutierre, M.A. & Mello, J.C.P. (2022) Pharmacobotanical study of Croton floribundus stem bark. Rodriguésia 73: e02302020. https://doi.org/10.1590/2175-7860202273032
- Gray, A. (1856) A manual of the botany of the Northern United States. 2nd ed. George P. Putnam & Co., New York, 739 pp. https://doi.org/10.5962/bhl.title.50405
- Gutschick, V.P. (1999) Biotic and abiotic consequences of differences in leaf structure. New Phytologist 143: 3–18. https://doi.org/10.1046/j.1469-8137.1999.00423.x
- Haberlandt, G. (1914) Physiological Plant Anatomy. MacMillan & Co., London, 777 pp.
- Heredia, A., Casado, C.G., Laguna, L., Reina, J.J., Serrano, J.M. & Dominguez, E. (1998) La cutícula vegetal: estructura y funciones. Ecology 12: 293–305.
- Holtzmeier, M.A., Stern, W.L. & Judd, W.S. (1998) Comparative anatomy and systematics of Senghas’s cushion species of Maxillaria (Orchidaceae). Botanical Journal of the Linnean Society 127: 43–82. https://doi.org/10.1111/j.1095-8339.1998.tb02087.x
- Humboldt, F.W.H.A., Bonpland, A.J.A. & Kunth, K.S. (1817) Nova Genera et Species Plantarum 2. Librairie Graeco-Latino-Germanicae, Paris, 401 pp.
- IUCN (2017) Guidelines for using the IUCN red list categories and criteria. Version 13. Prepared by the Standards and Petitions Subcommittee of the IUCN Species Survival Commission. IUCN, Gland and Cambridge. Available from: http://cmsdocs.s3.amazonaws.com/RedListGuidelines.pdf (accessed 27 November 2023)
- Johansen, D.A. (1940) Plant microtechnique. McGraw-Hill, New York, 523 pp.
- Juniper, B.E. & Jeffree, C. (1983) Plant surfaces. Edward Arnold Pub, London, 93 pp.
- Karabourniotis, G. & Fasseas, C. (1996) The dense indumentum with its polyphenol content may replace the protective role of the epidermis in some young xeromorphic leaves. Canadian Journal of Botany 74: 347–351. https://doi.org/10.1139/b96-043
- Karabourniotis, G., Liakopoulos, G., Nikolopoulos, D. & Bresta, P. (2020) Protective and defensive roles of non-glandular trichomes against multiple stresses: structure–function coordination. Journal of Forestry Research 31: 1–12. https://doi.org/10.1007/s11676-019-01034-4
- Klotzsch, J.F. (1853) Euphorbiaceae. In: Seemann, B.C. (Ed.) The botany of the voyage of H.M.S. Herald. Reeve & Co., London, pp. 99–106.
- Larcher, W. (2006) Ecofisiologia Vegetal. 3ª ed. Editora RiMa. São Carlos, São Paulo, 529 pp.
- Levin, D.A. (1973) The role of trichomes in plants defense. The Quarterly Review of Biology 48: 3–15. https://doi.org/10.1086/407484
- Linnaeus, C. (1753) Species plantarum. Laurentius Salvius, Stockholm, 1200 pp.
- Linnaeus, C. (1759) Systema Naturae ed. 10, 2. Laurentius Salvius, Stockholm, pp. 825–1384.
- Machado, S.R., Paleari, L.M., Paiva, É.A. & Rodrigues, T.M. (2015) Colleters on the inflorescence axis of Croton glandulosus (Euphorbiaceae): structural and functional characterization. International Journal of Plant Sciences 176: 86–93. https://doi.org/10.1086/678469
- Mauseth, J.D. (1988) Plant anatomy. The Benjamin Cummings Publishing Company, Inc., California, 560 pp.
- Metcalfe, C.R. & Chalk, L. (1983) Anatomy of the dicotyledons. Clarendon Press, Oxford, 297 pp.
- Mott, K.A., Gibson, A.C. & O’Leary, J.W. (1982) The adaptative significance of amphistomatic leaves. Plant, Cell & Environment 5: 455–460. https://doi.org/10.1111/1365-3040.ep11611750
- Müller Argoviensis, J. (1873) Euphorbiaceae. In: Martius, C.F.P. von & Eichler, A.W. (Eds.) Flora Brasiliensis 11(2). Fleischer, München, 752 pp.
- Naidoo, D., Naidoo, Y., Naidoo, G., Kianersi, F. & Dewir, Y.H. (2023) Histochemical analysis and ultrastructure of trichomes and laticifers of Croton gratissimus Burch. var. gratissimus (Euphorbiaceae). Plants 12: 772–791. https://doi.org/10.3390/plants12040772
- Ngumbau, V.M., Nyange, M., Wei, N., van Ee, B.W., Berry, P.E., Malombe, I., Hu, G.-W. & Wang, Q.-F. (2020) A new species of Croton (Euphorbiaceae) from a Madagascan lineage discovered in Coastal Kenya. Systematic Botany 45: 242–248. https://doi.org/10.1600/036364420X15862837791294
- Parkhurst, D.F. (1978) The adaptive significance of stomatal occurrence on one or both surfaces of leaves. Journal of Ecology 66: 367–383. https://doi.org/10.2307/2259142
- Pinto-Silva, N.P., De Souza, K.F., Silva, O.L.M., Vitarelli, N.C., Pereira, A.P.N., Soares, D.A., Sodré, R.C., Medeiros, D., Caruzo, M.B.R., Carneiro-Torres, D.S., Silva, M.J., Meira, R.M.S.A., Riina, R. & Feio, A.C. (2023) Trichomes in the megadiverse genus Croton (Euphorbiaceae): a revised classification, identification parameters and standardized terminology. Botanical Journal of the Linnean Society 203: 37–49. https://doi.org/10.1093/botlinnean/boad008
- Pyykkö, M. (1966) The leaf anatomy of East Patagonian xerophytic plants. Annales Botanici Fennici 3: 453–622.
- QGIS Development Team (2020) Quantum GIS geographic information system. Open-Source Geospatial Foundation Project. Available from: http://www.qgis.org/ (accessed 25 May 2023)
- Riina, R., Cumbicusb, N., Feio, A.C., Cerón, C.E., Meira, R.M.S.A. & Berry, P.E. (2015) A new species of dragon’s blood Croton (Euphorbiaceae) from South America with singular inflorescences. Webbia 70: 187–192. https://doi.org/10.1080/00837792.2015.1020129
- Riina, R., van Ee, B.W., Caruzo, M.B.R., Carneiro-Torres, D.S., Santos, R.F. & Berry, P.E. (2021) The Neotropical Croton sect. Geiseleria (Euphorbiaceae): Classification update, phylogenetic framework and seven new species from South America. Annals of the Missouri Botanical Garden 106: 111–166. https://doi.org/10.3417/2021669
- Rosa, A.C, Ferraro, A., Silva, R.H., Pott, V.J., Victório, C.P. & Arruda, R.C.O. (2021) Leaf anatomy of two medicinal Croton species: Contribution to plant recognition. Microscopy Research and Technique 84: 1685–1695. https://doi.org/10.1002/jemt.23727
- Rudall, P.J. (1987) Laticifers in Euphorbiaceae–a conspectus. Botanical Journal of the Linnean Society 94: 143–163. https://doi.org/10.1111/j.1095-8339.1987.tb01043.x
- Rudall, P.J. (1994) Laticifers in Crotonoideae (Euphorbiaceae): homology and evolution. Annals of the Missouri Botanical Garden 81: 270–282. https://doi.org/10.2307/2992097
- Sá-Haiad, B., Serpa-Ribeiro, A.C.C., Barbosa, C.N., Pizzini, D., Leal, D.O., Senna-Valle, L. & Santiago-Fernandes, L.D.R. (2009) Leaf structure of species from three closely related genera from tribe Crotoneae Dumort. (Euphorbiaceae s.s., Malpighiales). Plant Systematic and Evolution 283: 179–202. https://doi.org/10.1007/s00606-009-0229-x
- Sandquist, D.R. & Ehleringer, J.R. (1997) Intraspecific variation of leaf pubescence and drought response in Encelia farinosa associated with contrasting desert environments. New Phytologist 135: 635–644. https://doi.org/10.1046/j.1469-8137.1997.00697.x
- Silva, M.J., Sodré, R.C. & Berry, P.E. (2015) Novelties in Croton (Euphorbiaceae) from Goiás, Brazil. Systematic Botany 40: 162–167. https://doi.org/10.1600/036364415X686468
- Silva, M.J., Sodré, R.C. & Sales, M.F. (2014) A new species of Croton L. (Euphorbiaceae s.s.) from the Brazilian Cerrado. Systematic Botany 39: 216–221. https://doi.org/10.1600/036364414X678125
- Soares, D.A. (2013) Morfoanatomia foliar de espécies de Croton sect. Luntia (Euphorbiaceae) como contribuição para a taxonomia do gênero. MSc Dissertation, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 44 pp.
- Sodré, R.C., Alonso, A.A. & Silva, M.J. (2022) Revised delimitation of Croton campestris (Euphorbiaceae), including description of two new species, molecular phylogenetic, anatomical and micromorphological data. Acta Botanica Brasilica 36: e2021abb0163. https://doi.org/10.1590/0102-33062021abb0163
- Sodré, R.C., Berry, P.E. & Silva, M.J. (2017) The tribe Crotoneae (Euphorbiaceae, Crotonoideae) in the Chapada dos Veadeiros, Goiás, Brazil. Phytotaxa 321 (1): 1–59. https://doi.org/10.11646/phytotaxa.321.1.1
- Sodré, R.C. & Silva, M.J. (2017a) An overlooked new species of Croton section Geiseleria (Euphorbiaceae) from the Brazilian Cerrado, with a key to the species of this section occurring in the state of Goiás and in the Distrito Federal. Phytotaxa 329 (2): 127–138. https://doi.org/10.11646/phytotaxa.329.2.3
- Sodré, R.C. & Silva, M.J. (2017b) Croton rhodotrichus: a new species of Croton section Geiseleria (A. Gray) Baill. (Euphorbiaceae) from the state of Mato Grosso, Brazil. Systematic Botany 42: 338–345. https://doi.org/10.1600/036364417X695600
- Sodré, R.C. & Silva, M.J. (2018) Rediscovery of Croton hadrianii (Euphorbiaceae), a well distributed but long-forgotten species in Brazilian Amazon. Phytotaxa 349 (2): 141–151. https://doi.org/10.11646/phytotaxa.349.2.4
- Sodré, R.C., Sales, M.F., Berry, P.E. & Silva, M.J. (2019a) Taxonomic synopsis of Croton section Geiseleria (Euphorbiaceae) in Brazil, including description of a new species. Phytotaxa 417 (1): 1–105. https://doi.org/10.11646/phytotaxa.417.1.1
- Sodré, R.C. & Silva, M.J. (2020) A taxonomic reassessment of Croton grandivelus, including recognition of a new species, C. insignis, and the redefinition of C. fulvus (Euphorbiaceae). Phytotaxa 472 (3): 207–239. https://doi.org/10.11646/phytotaxa.472.3.1
- Sodré, R.C. & Silva, M.J. (2022) Croton sertanejus, a new species from Seasonally Dry Tropical Forest in Brazil, and redescription of C. echioides (Euphorbiaceae). European Journal of Taxonomy 839: 14–38. https://doi.org/10.5852/ejt.2022.839.1929
- Sodré, R.C., Souza, A.O., Alonso, A.A. & Silva, M.J. (2019b) Molecular, morphological, and anatomical data support a new species of Croton sect. Geiseleria (Crotonoideae, Euphorbiaceae). Plant Systematic and Evolution 305: 233–246. https://doi.org/10.1007/s00606-019-1566-z
- Solereder, H. (1908) Systematic anatomy of the dicotyledons. Clarendon Press, Oxford 1182 pp.
- Thiers, B. [continuously updated] (2023) Index Herbariorum. Part I: The herbaria of the world. New York Botanical Garden. Available from: http://sweetgum.nybg.org/science/ih/ (accessed 25 October 2023)
- Tozin, L.R.S., Silva, S.C.M. & Rodrigues, T.M. (2016) Non-glandular trichomes in Lamiaceae and Verbenaceae species: morphological and histochemical features indicate more than physical protection. New Zealand Journal of Botany 54: 446–457. https://doi.org/10.1080/0028825X.2016.1205107
- van Ee, B.W., Riina, R. & Berry, P.E. (2011) A revised infrageneric classification and molecular phylogeny of New World Croton (Euphorbiaceae). Taxon 60: 791–823. https://doi.org/10.1002/tax.603013
- Vitarelli, N.C., Riina, R., Cassino, M.F. & Meira, R.M.S.A. (2016) Trichome-like emergences in Croton of Brazilian highland rock outcrops: evidence for atmospheric water uptake. Perspectives in Plant Ecology, Evolution and Systematics 22: 23–35. https://doi.org/10.1016/j.ppees.2016.07.002
- Webster, G.L., Del-Arco-Aguilar, M.J. & Smith, B.A. (1996) Systematic distribution of foliar trichome types in Croton (Euphorbiaceae). Botanical Journal of the Linnean Society 121: 41–57. https://doi.org/10.1111/j.1095-8339.1996.tb00744.x
- Werker, E. (2000) Trichome diversity and development. Advances in Botanical Research 31: 1–35. https://doi.org/10.1016/S0065-2296(00)31005-9
- Weryszko-Chmielewska, E. & Chwil, M. (2014) Structures of Heracleum sosnovskii Manden. Stem and leaves releasing photodermatosis-causing substances. Acta Agrobotanica 67: 25–32. https://doi.org/10.5586/aa.2014.057