KEW BULLETIN (2016) 71:43 DOI 10.1007/S12225-016-9655-4
ISSN: 0075-5974 (print) ISSN: 1874-933X (electronic)
Buchnera tacianae (Orobanchaceae), a new species from the Brazilian cerrado Vinicius Castro Souza1 & Juliana de Paula-Souza2
Summary. A new species of Buchnera L. (Orobanchaceae) is described and illustrated. Buchnera tacianae V. C. Souza is endemic to the cerrado on the Central Plateau in Goiás state, Brazil, and is characterised by the indument of glandular trichomes that is unique among the Brazilian species of the genus. Further distinctive features and comments about its geographical distribution and conservation status, as well as an updated key for the Brazilian species of Buchnera are provided. Resumo. Uma nova espécie de Buchnera L. (Orobanchaceae) é descrita e ilustrada. Buchnera tacianae V. C. Souza é
endêmica do Cerrado no Planalto Central em Goiás, Brasil, e é caracterizada pelo indumento de tricomas glandulares que é único dentre as espécies brasileiras do gênero. Outras características diagnósticas e comentários sobre sua distribuição geográfica e estado de conservação, além de uma chave de identificação atualizada para as espécies brasileiras de Buchnera são fornecidos. Key Words. endemic, Scrophulariaceae, taxonomy.
Introduction Buchnera L. comprises approximately 100 species of parasitic herbs, widely distributed around the tropics (Bennett & Mathews 2006; Philcox 1965; Souza & Giulietti 2009). The genus was traditionally placed within the Scrophulariaceae with other hemiparasitic genera (sensu Bentham 1846, 1876; von Wettstein 1891), however recent phylogenetic analyses have supported it as a monophyletic clade of the Orobanchaceae (Bennett & Mathews 2006). Although the available results provide strong evidence of its monophyly, the relationship of Buchnera to other Orobanchaceae genera is still poorly understood as the sampling of its species in the studies carried out to date is still scarce, which also prevents biogeographical explanations for species diversity and distribution between the New and Old Worlds. Recent taxonomic surveys of Scrophulariaceae s.l. in Brazil (Souza & Giulietti 2009) detected a strikingly distinct new species endemic to the cerrado of the Central Plateau in Goiás state. From the 16 species occurring in the New World, 10 are found in Brazil, highlighting this country as an important centre of distribution for this group, and the necessity of further taxonomic studies in this region that has been under heavy anthropic threat. Buchnera tacianae V. C. Souza is characterised by its small, uni-nerved leaves and indument of glandular trichomes covering the whole
plant body, a unique feature among the Brazilian species of the genus. The new species is described and illustrated, and an updated identification key for the Brazilian taxa is provided, as well as comments on distribution and conservation status. This study is a continuation of others that have been developed in Orobanchaceae and Scrophulariaceae s.l., comprising Goiás state (Souza & Souza 1997), Brazil (Souza 2015) and the Neotropical region as a whole (Souza 2012), including the description of taxonomic novelties (Souza 2001; Souza et al. 2001).
Material and methods This work is a result of a larger study of Brazilian Scrophulariaceae s.l., which was based on intense field activities to observe living specimens, and consulted the following herbaria (acronyms according to Thiers 2015): ALCB, BHCB, BM, BOTU, BR, CEN, CEPEC, CESJ, COR, CPAP, EAC, EAN, ESA, ESAL, FUEL, G, HB, HBR, HRB, HRCB, HUCS, HUEFS, HUFU, HURG, IAN, ICN, INPA, IPA, JPB, K, LINN, M, MBM, MB, ML, MG, MO, NY, OUPR, OXF, P, PACA, PAMPUC, PEL, PEUFR, R, RB, SMDB, SP, SPF, SPSF, TEPB, UB, UEC, UPCB, URG, US, VIC, VIES. The new species’ conservation status was evaluated according to IUCN (2012) based on data of area of
Accepted for publication 24 July 2016. 1 Universidade de São Paulo, ESALQ, Herbário ESA, Av. Pádua Dias 11, C.P. 09, 13418-900, Piracicaba, SP, Brazil. e-mail:
[email protected] 2 Universidade Federal de São João del Rei, DECEB, Rua Sétimo Moreira Martins 188, C.P. 56, 35702-031, Sete Lagoas, MG, Brazil.
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occupancy (AOO) and extent of occurrence (EOO) obtained with the software GeoCAT. The IUCN default cell width of 2 km (Bachman et al. 2011) was used for the analysis.
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http://www.ipni.org/urn:lsid:ipni.org:names:77154533-1
base acute to rounded, margin entire, apex acute, glandular-pubescent, 1-nerved. Flowers arranged in dense terminal spikes, in solitary branches or less frequently 2 – 3-branched, bracts 2.5 – 3.5 × 1 – 2 mm, widely elliptic to ovate, apex acute, bracteoles 3 – 3.5 × c. 0.5 mm, narrowly oblong to narrowly lanceolate, sparsely glandular-puberulous; calyx 10nerved without intermediary nerves, sparsely glandular-puberulous with trichomes more dense along nerves, tube 3.5 – 4.5 mm, lobes triangular, apex acute, c. 1 mm long; corolla lilac, tube very sparsely puberulous, 6.5 – 9 mm, lobes 1.2 – 3.2 × 1.2 – 2.6 mm, obovate to subround, very sparsely glandular-puberulous or glabrous, ciliate. Capsule 5 – 6 × 3 – 4 mm, ellipsoid, apex rounded, apiculate. Figs 1, 2.
Erect herbs, 60 – 70 cm high, simple or rarely fewbranched, glutinous. Branches cylindrical, glandularpubescent or glandular-puberulous, internodes 5 – 17 mm. Leaves opposite, turning alternate and more spaced out towards the apex of the branch, 10 – 18 × 3 – 6 mm, sessile, narrowly elliptic to elliptic, oblanceolate or less frequently lanceolate,
RECOGNITION. The new species is readily recognised among other Brazilian species by its glutinous body covered with glandular trichomes (Fig. 2). DISTRIBUTION. Endemic to cerrados around the municipalities of Niquelândia and Campinaçu in northern Goiás, with a single collection further south in Caldas Novas (Maps 1, 2).
Taxonomic Treatment Buchnera tacianae V. C. Souza, sp. nov. Type: Brazil, Goiás, Niquelândia, Serra Negra, Córrego Buritizinho, estrada que vai para Rosareana, Cerrado arenopedregoso, 450 m, 23 July 1995, Cavalcanti, G. P. Silva, Rezende, Gualda, M. C. Silva & Carvalho 1631 (holotype CEN 25091!).
Fig. 1. Buchnera tacianae. A habit; B detail of the inflorescence covered by the distinctive glandular trichomes. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2016
PHOTOS: V. C. SOUZA.
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Fig. 2. Buchnera tacianae. A habit; B leaf; C flower, with a detail of the glandular trichomes; D detail of the inner corolla tube, showing the stamens; E stamen; F immature fruit; G gynoecium; H cross section of the ovary; J mature fruit inside the persistent calyx. DRAWN BY ROGERIO LUPO.
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Map 1. Distribution of Buchnera tacianae (red dots) in the cerrado (hatched area).
SPECIMENS EXAMINED. BRAZIL. Goiás, Caldas Novas, Parque Estadual da Serra de Caldas Novas, Cerrado pedregoso, trilha do paredão, 751 m, 17°46.00'S, 48°39.30'W, 7 Aug. 2009, Moura et al. 709 (ESA, UEC). Campinaçu, estrada Niquelândia-Campinaçu, Cerrado arenoso, 420 m, 14°03'S, 48°30'W, 6 Oct. 1995, Cavalcanti et al. 1804 (CEN). Niquelândia, marquem esquerda do Rio Traíras, a 10 km da ponte sobre este rio (descendo) próxima a Indaianápolis, Cerrado s.str. com marcas de incêndios periódicos, solo areno-argiloso com forte
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camada superficial de cascalho, área de influência da UHE Serra da Mesa, 470 m, 14°14'S, 48°34'W, 19 June 1992, Walter et al. 1532 (CEN, RB). Niquelândia, 4 km do povoado de Muquém em direção a Niquelândia, Cerrado em solo compacto e pedregoso, 495 m, 14°31'14"S, 48°09'08"W, 8 May 1998, M. A. Silva et al. 3803 (IBGE, NY). HABITAT. Usually found in dry, sandy, compact soils, frequently covered by a thick layer of loose rocks. CONSERVATION STATUS. As the estimated area of occupancy (AOO) of Buchnera tacianae is 16 km2 it may be categorised as endangered based on IUCN criterion B2 (AOO less than 500 km2), and a further analysis of the available data for the distribution of the species confirms this status (EN B2a, b). There is a single record of Buchnera tacianae collected in a conservation unit, the Serra de Caldas Novas State Park, and this the only known population of the species outside its core area of distribution in Niquelândia-Campinaçu region. Several unsuccessful attempts were made to recollect the species at the northern limit of its occurence, and since all known herbarium samples were gathered in the area of influence of the UHE Serra da Mesa (Map 2), it is highly probable that these populations went extinct aft er t he i nstall ation of the hydroelectric power plant. Future field activities in the southern limit of distribution of Buchnera tacianae are thus encouraged, to support conservation policies in the area. ETYMOLOGY. Buchnera tacianae is a tribute to Dr Taciana Barbosa Cavalcanti, a prolific collector and well-versed researcher of the cerrado Flora.
Map 2. Distribution of Buchnera tacianae (blue dots) showing the disjunction between its core population in NiquelândiaCampinaçu area and the southernmost population in Caldas Novas (extracted from GeoCAT). © The Board of Trustees of the Royal Botanic Gardens, Kew, 2016
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Key to the species of Buchnera in Brazil (updated from Souza & Giulietti 2009) 1.
Leaves 1-nerved 2. Plants glutinous, covered with glandular trichomes . . . . . . . . . . . . . . . . . . . . . . . B. tacianae V. C. Souza 2’. Plants not glutinous, glandular trichomes absent 3. Stem and leaves glabrous; calyx c. 0.4 cm long, with lobes not ciliate . . . . . . . . . B. tenuissima Philcox 3’. Stem and leaves hispid-scabrous (or less frequently the stem glabrous); calyx 0.7 – 0.9 cm long, with ciliate lobes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. palustris (Aubl.) Spreng. 1’. Leaves 3 – 5-nerved 4. Indument formed entirely or partially by uncinate trichomes . . . . . . . . . . . . . . . . . . . B. ternifolia Kunth 4’. Uncinate trichomes absent 5. Calyx glabrous or only ciliate 6. Leaves adpressed to the stem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. juncea Cham. & Schltdl. 6’. Leaves not adpressed to the stem. . . . . . . . . . . . . . . . . . . . . . . . B. lavandulacea Cham. & Schltdl. 5’. Calyx pilose or pilose either along or between the nerves 7. Calyx entirely pubescent or pilose only between the nerves 8. Calyx with 10 main nerves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. integrifolia Larrañaga 8’. Calyx bearing intermediate nerves between the 10 main nerves . . . . . . . . . . . B. rosea Kunth 7’. Calyx pilose only along the nerves 9. Calyx with 10 main nerves 10. Corolla tube externally glabrous . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. longifolia Kunth 10’. Corolla tube externally sparsely pubescent . . . . . . . . . . . B. amethystina Cham. & Schltdl. 9’. Calyx bearing intermediate nerves between the 10 main nerves . . . . . . . . . . . B. rosea Kunth
Acknowledgements The authors thank the team of Goiás State University, campus Morrinhos, as well as the directors of Caldas Novas State Park for the support given to field activities in this region, and the keepers of the consulted herbaria for making their collections available. The first author would also like to thank CNPq for providing a scientific productivity grant. References Bachman, S., Moat, J., Hill, A. W., de la Torre J. & Scott, B. (2011). Supporting Red List threat assessments with GeoCAT: Geospatial Conservation Assessment Tool. http://geocat.kew.org/. Accessed 17 Jan. 2015. Bennett, J. R. & Mathews, S. (2006). Phylogeny of the parasitic plant family Orobanchaceae inferred from phytochrome A. Amer. J. Bot. 93(7): 1039 – 1051. Bentham, G. (1846). Scrophulariaceae. In A. De Candolle (ed.), Prodromus 10: 180 – 586. Victoris Masson, Paris. ____ (1876). Scrophulariaceae. In: G. Bentham & J. D. Hooker (eds), Genera Plantarum, Vol. 2: 913 – 980. Reeve & Co., London. IUCN (2012). IUCN Red List Categories and Criteria. Version 3.1. Second Edition. IUCN Species Survival Commission, Gland and Cambridge.
Philcox, D. (1965). Revision of the New World species of Buchnera L. (Scrophulariaceae). Kew Bull. 18(2): 275 – 316. Souza, V. C. (2001). Novidades taxonômicas em Esterhazya J. C. Mikan (Scrophulariaceae). Bradea 8(36): 221 – 226. ____ (2012). Neotropical Orobanchaceae. In: W. Milliken, B. Klitgård & A. Baracat (2009 onwards), Neotropikey — Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/ neotropikey/families/Orobanchaceae.htm. Accessed 7 May 2015. ____ (2015). Orobanchaceae. In: Lista de Espécies da Flora do Brasil. Jardim Botânico do Rio de Janeiro. Available in: . Accessed 07 Mai. 2015. ____, Elias, S. I. & Giulietti, A. M. (2001). Notes on Agalinis (Scrophulariaceae) from Brazil. Novon 11 (4): 484 – 488. ____ & Giulietti, A. M. (2009). Levantamento das espécies de Scrophulariaceae sensu lato nativas do Brasil. Pesquisas, Botânica 60: 7 – 288. Available at http://www.anchietano.unisinos.br/publicacoes/botanica/botanica60/artigo1.pdf#page=14&zoom=auto,184,100. ____ & Souza, J. P. (1997). Flora de Goiás e Tocantins — Coleção Rizzo: Scrophulariaceae. Universidade Federal de Goiás, Goiânia. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2016
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Thiers, B. (2015). Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden's Virtual Herbarium. http:// sweetgum.nybg.org/ih/. Accessed 5 Feb. 2015.
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von Wettstein, R. (1891). Scrophulariaceae. In: A. Engler & K. Prantl (eds), Die Natürlichen Pflanzenfamilien, Vol. 4, Part 3b, pp. 39 – 107. Wilhelm Engelmann, Leipzig.
