New taxa of Catasetum (Orchidaceae, Catasetinae) from Mato Grosso, Brazil Adarilda Petini-Benelli1 & Célia Regina A. Soares-Lopes2 ________________________________ 1Department of Ecology and Botany, Community Ecology Laboratory, Universidade Federal de Mato Grosso. Av. Fernando Correa da Costa, Bairro Boa Esperança, Cuiabá 78060-900, Mato Grosso, Brazil; [email protected] 2Herbário da Amazônia Meridional, Universidade do Estado de Mato Grosso (UNEMAT), Rodovia MT 208, km 147, Bairro Jardim Tropical, Alta Floresta 78580-000, Mato Grosso, Brazil. ________________________________ Abstract Catasetum paranaitense, a new species of Catasetum, is recorded for the southern Amazon region of Mato Grosso. The species presents unique characters and stands out alongside the other species occurring in the region, being compared only to Catasetum osakadianum and C. multifidum. Recorded in an area bounded by the Paranaíta and Teles Pires rivers, in the municipality of Paranaíta, State of Mato Grosso, the species is described, illustrated and has its status discussed in this paper. A new variety is also described and illustrated: the estroisii form. Résumé Une nouvelle espèce de Catasetum, Catasetum paranaitense, est rapportée pour la région amazonienne méridionale du Mato Grosso (Brésil). Elle présente des caractères uniques qui la distinguent des autres espèces présentes dans la région, notamment Catasetum osakadianum et Manuscrit reçu le 15/06/2017 Article mis en ligne le 09/09/2017. - pp.31-43 C. multifidum, auxquelles elle est comparée. L'espèce a été observée dans une zone délimitée par les rivières Paranaíta et Teles Pires, dans le Municipio de Paranaíta (Mato Grosso). Elle est décrite et illustrée et son statut de conservation est discuté. Une variante de couleur est également décrite au rang de forme sous le nom de estroisii et illustrée. Resumo Uma nova espécie de Catasetum é registrada para a Amazônia Meridional mato-grossense. A espécie apresenta caracteres únicos e destaca-se junto às demais ocorrentes na região, sendo parcialmente comparada a Catasetum osakadianum e a C. multifidum. Registrada em área delimitada pelos rios Paranaíta e Teles Pires, no município de Paranaíta, Estado de Mato Grosso, é descrita, ilustrada e tem seu status discutido no presente trabalho. Keywords: Biodiversity, Catasetinae, Conservation, Paranaita River. Mots clés : Biodiversité, Catasetinae, conservation, Rivière Paranaíta. Palavras chave: Biodiversidade, Catasetinae, Conservação, Rio Paranaíta. Introduction The State of Mato Grosso has been a real reservoir of biological diversity, where there are many species still unknown to science (Petini-Benelli et al., 2015). The portion of Mato Grosso in the Southern Amazon region has contributed to enrich the list of new taxa, for example, Catasetum × apolloi Benelli & Grade (Petini-Benelli & Grade, 2008; 2012), Catasetum × altaflorestense Benelli & Grade (Petini-Benelli & Grade, 2010), Acianthera gradeae Chiron & Benelli (Chiron & Petini-Benelli, 2012), Catasetum telespirense Benelli & Soares-Lopes (Petini-Benelli & Soares-Lopes, 2015), Catasetum × canaense Benelli (Petini-Benelli, 2016a) and Catasetum colidense Engels, Ferneda Rocha & Benelli (2016). With these new records the genus Catasetum L.C.M. Richard ex Kunth comprises of 37 species and two natural hybrids for the State of Mato Grosso (Petini-Benelli et al., 2007; Petini-Benelli, 2012; Petini-Benelli et al., 2015; 2016). The genus has a controversial number of valid species: 130 according to Romero-González (2009), while 194 species are listed in the World Checklist of Selected Plant Families (Govaërts et al., 2014), distributed throughout the Neotropic Region of the Americas. This study aimed to describe and illustrate a new species, recently discovered in the State of Mato Grosso during activities relating to the project “Filogenia de 32 Catasetum Rich. ex Kunth and the Monograph of the genus for the State of Mato Grosso, Brasil”. Materials and methods The first examined samples were donated by Clarice de Oliveira Estrois Moreira, in 2010, during a visit to Fazenda Itamarati. The property, located in the municipality of Paranaíta, northern Mato Grosso, is bathed by the rivers Teles Pires and Paranaíta. As soon as the plants flowered, the exsiccata were prepared following Petini-Benelli (2016b) and deposited in UFMT. Some flowers were kept in the Flores Net Collection, with numbers assigned as material-witness. Additional materials of the new taxa which compose the HERBAM collection were analyzed and included. The corresponding plants were also collected on the Teles Pires river, in a nearby area. Specimens of the new taxon were compared with Catasetum collections of MG, UFMT, HERBAM and RB (Thiers, 2016) as well as data from protologues of similar species. Taxonomic treatment Catasetum paranaitense Benelli & Soares-Lopes, sp. nov. Type : Brazil, Mato Grosso, Paranaíta, on the left bank of the Teles Pires river. Fazenda Itamarati, 9°24’47”S; 56°33’55”W, 247 m elev., 17-I-2013. A. Petini-Benelli ADA003A (holotype UFMT 40833! ♂). Fig. 1 and 2. Haec species Catasetum multifidum F.E.L. Miranda et Catasetum osakadianum M.F.F. Silva & A.T. Oliveira similies est sed labelli structura formaque et peculiaribus callis fimbriisque, differt. Epiphyte herb of shady riparian forest; threadlike roots arising from the base of the pseudobulb on a short rhizome; pseudobulbs fusiform, 50-90 × 15-20 mm, aggregated, spindle-shaped, covered by remaining leaf sheaths, whitish; leaves 8-10 on each pseudobulb, oblong-lanceolate, 20-30 × 2.5- 4.5 cm, arched, very sharply acute apex, with canaliculate pseudo petiole, the two basal leaves fallen before maturation; inflorescence basal, 10-30 × 2.5-3 mm, a raceme up to eight resupinate flowers in the upper half of the inflorescence; male inflorescence gently tumbled, standing at a 45° angle from the pseudobulb, becoming semi-pending with the weight of the flowers; steril bract amplexicaul, triangular, 8-10 × 4 mm, pointed apex, involving raceme nodes; flowers vinaceous or reddish-brown; pedicel ca. 28-30 × 2 mm, arched, wrapped in bracts identical to the steril bracts, New Catasetum from Brazil – Petini-Benelli & Soares-Lopes Fig. 1: Catasetum paranaitense A. general view of the flowering plant, male flowers; B. flower, frontal view; C. labellum, abaxial view; D. male flower from the estroisii variety, frontal view, labellum; E. inflorescence. A-C from Petini-Benelli ADA003A (UFMT); D-E from Fernández s.n. (UFMT). 34 Fig. 2: Catasetum paranaitense A. general view of the flowering plant, male flowers; B. male flower with distended floral parts: a. dorsal sepal; b. petal; c. lateral sepal; d . labellum 1-3 front view, variable forms; e. labellum view abaxial; f. labellum whole and New Catasetum from Brazil – Petini-Benelli & Soares-Lopes sectioned side view; C. column: a. column with pollinarium; b. anther cover; c. pollinia; A from Soares et al. 5095 (HERBAM); B-C from Petini- Benelli ADA003A (UFMT); d from Soares et al. 5659 (HERBAM); d from 2 3 Soares et al. 5208 (HERBAM). including the ovary ca. 8 × 3 mm; sepals oblong-lanceolate with acute apex, the dorsal 30-32 × 8.5-9 mm, erect, concave, the lateral 32-34 × 11-12 mm, somewhat pendulous and concave, facing forward, partly surrounding the labellum, with margins somewhat revolute; petals oblanceolate, 30-33 × 7- 8 mm, acute, erect, somewhat convex, dorsaly reflexed to tubular, almost entirely covered by the dorsal sepal, a little lighter than the sepals; labellum briefly sacciform, 18-20 × 11-12 mm without fimbriae, ca. 5 mm deep, projected forward, summit facing down, lateral lobes modified in ciliate appendices which are divided into very thin and delicate branches; at the base of the labellum, a set of calli going towards the bag in two series, the central one being first high and prominent, curved and pointed, with apex peaked into very short cilia; often, this callus is followed by another callus which are sharply lowered and lengthened to the bottom of the bag or ending abruptly and projecting into the labellum apex, up to ca. 4 × 8 mm in the base; around this central callus, another series of calli, crescent-shaped, consisting of small aligned teeth, from filaments coming from the central callus, embossed, looking as radial venules; the portion of the labellum which surrounds the bag, from the first curvature to the frontal lobe division, with two rows of ciliate structures, up to 7 mm long, along each margin of the lateral lobes, one inside with the cilia facing the center, lying on the opening of the bag, and one external with the cilia facing outward; the frontal lobe divided into three parts, the two lateral ones fimbriate and multiciliate, and the middle one acute at the apex with a well-differentiated callus, long and filamentous, resembling a thickened cilium, up to 5 mm long, sometimes short and densely clustered, looking as bristles of a brush; column straight, ca. 20 × 7 mm, base narrowed, subtriangular, dorsally brown vinaceous, ventrally yellowish, which highlights the antennas, ca. 9 × 0.5 mm, parallel, positioned on the sides of central callus, with a dark vinaceous stain; anther subtriangular, rostrate, yellow; rostellum long, ca. 7 × 2 mm, apiculate, dorsally vinous brown, ventrally yellowish. Female flower and fruit not seen. 36 Fig. 3. Distribution area of C. paranaitense in the Mato Grosso State Map projection: http://www.simplemappr.net/api/ Etymology: referring to the location where the samples of the present species were collected. Distribution: only two populations were recorded in the municipality of Paranaíta, in the Southern Brazilian Amazon region of the State of Mato Grosso (Fig. 3). Phenology: this species was found flowering between October and May, in consecutive blooms even after the leaves fell. Conservation Status: according to IUCN (2001) criteria, C. paranaitense probably falls under the endangered species category (EN), because it is rarely found in the distribution area referred to here. Only two populations were recorded with approximately 20 individuals per population, being a very low number for conservation viability of the species. Material examined: BRAZIL. Mato Grosso. Paranaíta. UHE Teles Pires, 12- I-2012, C.R.A. Soares et al. 5095 (HERBAM 7564) (♂); idem, 25-II-2012, C.R.A. Soares et al. 5384 (HERBAM 7782) (♂); idem, 27-III-2012, C.R.A. Soares et al. 5659 (HERBAM 8057) (♂); idem, 7-II-2013, M. Barros & C. Correa 25 (HERBAM) (♂); idem, 14-XI-2012, M. Barros & C. Correa CC763-15A (HERBAM) (♂); idem, 14-XI-2012, M. Barros & C. Correa CC763-15B New Catasetum from Brazil – Petini-Benelli & Soares-Lopes (HERBAM) (♂); Paranaíta. Fazenda Itamarati, 09º43’54”S; 56º37’26”W, 239 m elev., 15-V-2012, A. Petini-Benelli ADA003B (UFMT 40847) (♂); idem, 4-X- 2013, A. Petini-Benelli ADA207 (RB 445576; Spirit ADA207) (♂); idem, 9°24’47”S; 56°33’55”W, 247 m elev., 25-IX-2013, A. Petini-Benelli ADA189 (UFMT 41185) (♂). Catasetum paranaitense Benelli & Soares-Lopes forma estroisii Benelli, f. nov. Type: Brazil, Mato Grosso: Paranaíta, 1-II-2012. C.R.A. Soares et al. 5208 (holotype: HERBAM 7606!) (♂). Fig. 2, E. The estroisii form differs from the type mainly as regards color, since it has intensely bright green petals and sepals, and a totally white labellum. Also, the callus is bright white. Column entirely green, which stresses the yellowish-green pollinarium. Antennae light green. Material examined: BRAZIL. Mato Grosso. Paranaíta, UHE Teles Pires, 26- XII-2011, C.R.A. Soares et al. 4913 (HERBAM 7382) (♂); idem, 22-X-2012, M. Barros & C. Correa CC751 (HERBAM) (♂); Paranaíta, margem esquerda do rio Teles Pires, Fazenda Itamarati, 9°24’47”S, 56°33’55”W, 247 m elev., 15-V-2012, A. Petini-Benelli ADA003B, flowering in 17-I-2013 (UFMT 40847) (♂); idem, 29-X-2013, A. Petini-Benelli ADA230 (RB 449649; Spirit ADA230) (♂); idem, 15-V-2012, A. Petini-Benelli ADA0286, flowering in 18-XI-2013 (UFMT 41184) (♂). Catasetum paranaitense and related species: Catasetum paranaitense may be included in the Catasetum barbatum (Lindley) Lindley complex, subgenus Catasetum, section Isoceras (Mansfeld) Senghas, subsection Isoceras, with fully parallel antennas. This complex comprises of approximately 20 species, and in this set of species, the principal feature is its labellum with a lot of cilia (more or less grouped), and the petals and sepals densely recovered with brown spots. Catasetum paranaitense is related to C. osakadianum M.F.F. Silva & A.T. Oliveira and C. multifidum F.E.L. Miranda. The species shares with C. osakadianum the double row of cilia on the front of the labellum and the division in form of trident, but differs in the shape of these structures that are more elongated and pluriciliate as well as the labellum being more elongated. Likewise, C. paranaitense shares with C. multifidum the plural- division of cilia, which are broken down four times in C. paranaitense. 38 However, in the latter fimbriae or cilia are so plentyful and so dense that they hide other labellum structures, while in the first taxon fimbriae are arranged in a single layer on the labellum margin. Moreover, C. multifidum presents all the floral segments densely marked with brown stains, a characteristic pigmentation pattern in the C. barbatum complex. This pattern is dominant in hybrids that involve any species of this complex, but does not appear in C. paranaitense, which leads us to totally rule out the possibility of it being a result of hybridization with C. multifidum. The similarity of characters between C. paranaitense and C. osakadianum would be only in relation to coloring – completely vinaceous in type form, and green with white labellum in the estroisii variety of C. paranaitense and in the albina form of C. osakadianum, respectively. Besides, we can highlight a distinctive character: in C. paranaitense, the white labellum of estroisii variety keeps immaculate until the flower falls, while in C. osakadianum, the white of the albina form progressively gives way to yellow. Another factor to consider among the three species is the fact that Catasetum osakadianum and C. multifidum were recorded only for the State of Rondônia (Barros et al., 2015), whereas no record of the new species was recorded there. Catasetum osakadianum was described and registered for the Porto Velho area (with rare collections) and C. multifidum was recorded near Ji-Paraná. C. paranaitense occurs at a distance of about 1,000 km. Thus, we understand that the similarities observed in C. paranaitense (such as the shape of the labellum resembling C. osakadianum, and the multi-split fringes of the edges and labellum apex, resembling C. multifidum) are not sufficient to fuse it into one or other species. Still, C. paranaitense stands out from all species registered in Mato Grosso by its coloring. The most common form, and that which we consider as the type, is the wine or dark reddish-brown color, with even the column showing this coloring, sometimes just a little clearer. The labellum in C. paranaitense is the only structure with significant morphological changes in the species and these variations confirm the unique identity of this species (see Fig. 1 and 2 and Tab. 1). New Catasetum from Brazil – Petini-Benelli & Soares-Lopes C. multifidum C. osakadianum C. paranaitense Inflorescence racemose and arched erect upright until short pendent Flower distribution grouped in terminal distributed in the sparsely distributed half upper third from the middle portion Flower size 70-75 mm 55-62 mm 60-65 mm distended Peduncle (incl. 38-45 × 3 mm 20-22 × 2 mm 28-32 × 2 mm ovary) Dorsal sepal oblanceolate lanceolate oblanceolate 30-35 × 8-9 mm 32-34 × 8-10 mm 30-32 × 8.5-9 mm Lateral sepal oblanceolate, erect, lanceolate, arched oblanceolate, semi- reflex, down, pendent, 30-35 × 8-9 mm 33-35 × 8-9 mm 32-34 × 11-12 mm not surounding the not surounding the facing forward and labellum labellum partially surounding the labellum Petals oblanceolate lanceolate oblanceolate, dorsally reflex 30-34 × 7-8 mm 29-30 × 7-8 mm 30-33 × 7-8 mm Labellum lateral lobes with fleshy, lateral lobes laterals lobes with multiple ciliate with split edges, many very fine and appendices, designed denticulate into delicate branches out, terminal lobe in fimbriated, terminal an isthmus format lobe triangular, apiculate 18 mm long × 14 mm 18–20 mm long × 5–7 18–20 mm long × 11– width × 5 mm deep mm width × 9 mm 12 mm width × 5 mm deep deep Tab. 1: Comparison of floral morphology in Catasetum multifidum, C. osakadianum and C. paranaitense. Characters to distinguish these species. 40