Luetzelburgia amazonica (Leguminosae: Papilionoideae: Vataireoid clade), a new species from Brazilian Amazonia
The new large tree species Luetzelburgia amazonica D. B. O. S. Cardoso, L. P. Queiroz & H. C. Lima is described, illustrated and discussed based on collections from the state of Rondônia in Brazil. It is the only species of the genus occurring in the Amazon basin. Luetzelburgia amazonica resembles L. trialata (Ducke) Ducke based on the number and morphology of leaflets, fruit size and the dark brown sericeous indumentum on the inflorescence, but differs mainly in its larger flowers, pinkish petals and very distinct standard petal shape.
Key WordsBrazil plant diversity Sophoreae s.l. taxonomy
A nova espécie de árvore Luetzelburgia amazonica D. B. O. S. Cardoso, L. P. Queiroz & H. C. Lima é descrita, ilustrada e discutida baseada em coleções do estado de Rondônia, Brasil, sendo, portanto, a única espécie do gênero que ocorre na Bacia Amazônica. Luetzelburgia amazonica se parece com L. trialata (Ducke) Ducke pela morfologia e número de folíolos, tamanho dos frutos e o indumento seríceo marrom escuro da inflorescência, mas difere principalmente pelas flores maiores com pétalas róseas e morfologia do estandarte bem distinta.
The genus Luetzelburgia Harms (Leguminosae, Papilionoideae) comprises about 14 species that occur predominantly in seasonally dry tropical forests of eastern Brazil (Cardoso et al.2008), whereas phylogenetically related genera (Vatairea Aubl. and Vataireopsis Ducke) of the Vataireoid clade have largely diversified in the Amazon rain forests (Pennington et al.2005; Cardoso et al.2010). The monophyly of Luetzelburgia has been demonstrated in an on-going molecular phylogenetic analysis of the Vataireoid legumes (Cardoso et al. unpublished data), within which the genus is defined by the following morphological synapomorphies: petals crimped and covered longitudinally by sericeous indumentum outside of the middle portion, standard petal mostly oblong to obovate and with auricles, wing-like and keel-like petals undifferentiated in shape and biauriculate, wing-like petals covered by lunate-lamellate sculpturing in the entire outer surface, staminal filaments basally connate and samaras with lateral wings on side of seed chamber.
As a result of a forthcoming taxonomic revision of Luetzelburgia, we describe and illustrate a new species that represents the first record of the genus in the Amazon domain and highlights its biogeographical history linked with the rain forest lineages of the Vataireoid legumes (Cardoso et al.2010).
Luetzelburgia amazonicaD. B. O. S. Cardoso, L. P. Queiroz & H. C. Limasp. nov.Luetzelburgia trialata (Ducke) Ducke foliolis grabris in numero et morphologia similaribus, fructibus grandibus et indumento sericeo brunneo inflorescentiae similis, sed floribus majoribus (13 – 16 mm longo non 8 – 10 mm), petalis roseis (non sanguineis) et vexillo obovali majoribusque (11 – 14 × 5.8 – 6.8 mm) non oblongo (et 7 – 9 × 2 – 2.8 mm) praecipue differt. Typus: Brazil, Rondônia, Município de Porto Velho, Ferreira et al. 8908 (holotypus NY!; isotypi F!, INPA!, K, MBM!, MO!).
distribution. South America: Brazil. To date only known from two localities in the state of Rondônia.
specimens examined. brazil. Rondônia: Município de Porto Velho, estrada da Serra do Balateiro a 3 km da Vila Campo Novo, 10°35'S, 63°39'W, 23 – 24 April 1987, fl, Ferreira et al. 8908 (holotype NY; isotypes F, INPA, K n.v., MBM, MO); Município de Campo Novo de Rondônia, estrada da área antiga de mineração de cassiterita, no sopé da Serra do Balateiro, 10°37'18''S, 63°37'03''W, 286 m, 2 May 2010, st, Cardoso et al. 2920 (CEPEC, CTES, F, HUEFS, INPA, K, MBM, MG, MIRR, MO, MONT, NY, RB, SP); Município de Alvorada d’Oeste, Rodovia Alvorada d’Oeste – N. Brasilândia, Km 23, linha 64, lado direito, 25 Sept. – 31 Oct. 1986, st, Lobato et al. 402 (MG); Município de Porto Velho, c. 5 km S of Campo Novo, on road to old mining area at Balateiro, 10°38'S, 63°37'W, 300 m, 23 April 1987, fl, Nee 34997 (F, INPA, K n.v., MO, NY, SP); ibid., 23 April 1987, fl, Nee 35002 (F, INPA, K n.v., MO, NY, SP); Município de Alvorada d’Oeste, rodovia 469-L64, 25 June 1987, fr, Maciel et al. 1313 (RB).
habitat. Although occurring in the Brazilian Amazon domain, Luetzelburgia amazonica seems to conserve the idiosyncratic biogeographical predilection of the genus to seasonally dry forests (Cardoso et al.2010). As we confirmed in the field at Serra do Balateiro (Campo Novo de Rondônia), the habitat of L. amazonica is mostly semi-deciduous forest with granite boulders, a common transitional vegetation type in the southern periphery of Amazonia (Daly & Silveira 2010) that matches well with the broad concept of the neotropical seasonally dry tropical woodlands (Pennington et al.2000).
conservation status.Luetzelburgia amazonica should be considered critically endangered in the category B1abiii of IUCN (2001), because it is only known from a few collections in severely fragmented areas which are in relatively close proximity (distance between the two furthest areas is c. 150 km). Additionally, the region at Serra do Balateiro, where the type specimen was collected, has long been threatened by the deforestation impact of the cassiterite (tin ore) mining.
phenology.Luetzelburgia amazonica has been collected in flower in April and in fruit in June.
etymology. The epithet amazonica emphasises the first record of the genus Luetzelburgia in the Amazon.
notes.Luetzelburgia amazonica is the only species of the genus occurring in the Amazon. With a remarkable estimated height of 35 m (Nee 34997), it seems to be the tallest species in the genus. This new species closely resembles the Atlantic Forest endemic L. trialata (Ducke) Ducke based on the similar number and morphology of the glabrous leaflets, a relatively large samara and the dark brown sericeous indumentum densely covering the inflorescence axes and calyces. However, L. amazonica differs from L. trialata most notably in its larger flowers (13 – 16 mm long vs 8 – 10 mm long). It can also be differentiated from L. trialata by its early deciduous bracteoles (vs persistent), petals predominantly pinkish (vs dark reddish) and the standard petal obovate in outline and larger, 11 – 14 mm long and the apex 5.8 – 6.8 mm broad (vs slightly oblong and 7 – 9 × 2 – 2.8 mm).
We are grateful to the curators of the following herbaria for the loan of collections: F, INPA, MBM, MO, NY, RB and SP; Cássio van den Berg for kindly translating the diagnosis into Latin; Carla de Lima for the beautiful line drawing; and two anonymous reviewers for very constructive comments. DBOS Cardoso also thanks Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA) for issuing collecting permissions (SISBIO 22753-1 and 22824-1) and Tânia Moura, Sr. Joilson Marinho, Sr. Cícero and Sra. Irene for their valuable and friendly assistance during fieldwork in the state of Rondônia. Financial support during fieldwork was partially sponsored by the Programa de Pesquisa em Biodiversidade do Semi-árido (PPBIO). This paper is part of the PhD thesis of DBOS Cardoso prepared in the Programa de Pós-graduação em Botânica (PPGBot-UEFS) and supported by a grant from CNPq (Process 143116/2008-8).
- ____ (2010). Diversification of the Vataireoid Legumes and Biogeography of Neotropical Dry Forests. Abstracts of the V International Legume Conference, 8 – 14 August, Buenos Aires.Google Scholar
- Daly, D. C. & Silveira, M. (2010). Affinities of the Acre Flora: a First Analysis. In: The New York Botanical Garden, Floristics and Economic Botany of Acre, Brazil. Website: <http://www.nybg.org/bsci/acre/www1/affinities.html>, accessed on 9 Sept. 2010.
- IUCN (2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland and Cambridge.Google Scholar
- ____, Stirton, C. H. & Schrire, B. D. (2005). Tribe Sophoreae. In: G. Lewis, B. Schrire, B. Mackinder & M. Lock (eds), Legumes of the World, pp. 227 – 249. Royal Botanic Gardens, Kew.Google Scholar