Abstracts

INTRODUCTION

Spiranthinae Lindl. ex Meisner comprises about 42 genera and 470 species (Chase et al. 2003, Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.) of predominantly terrestrial orchids (Salazar et al. 2003Salazar GA, Chase MW, Soto Arenas MA and Ingrouille M. 2003. Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences. Amer J Bot 90: 777-795.). This subtribe has two main biodiversity centers, one in Mexico and Central America and the other in Southern and Southeastern Brazil (Dressler 1993Dressler RL. 1993. Phylogeny and classification of the orchid family. Dioscorides Press, Portland Oregon, 316 p., Balogh 1982Balogh P. 1982. Generic redefinition in subtribe Spiranthinae (Orchidaceae). Amer J Bot 69: 1119-1132.).

Spiranthinae has been supported as a monophyletic group in several phylogenetic studies (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278., Figueroa et al. 2008Figueroa C, Salazar GA, Zavaleta HA and Engleman EM. 2008. Root character evolution and systematics in Cranichidinae, Prescottiinae and Spiranthinae (Orchidaceae, Cranichideae). Ann Bot 101: 509-520., Salazar et al. 2003Salazar GA, Chase MW, Soto Arenas MA and Ingrouille M. 2003. Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences. Amer J Bot 90: 777-795., 2009Salazar GA, Cabrera LI, Madriñán S and Chase MW. 2009. Phylogenetic relationships of Cranichidinae and Prescottiinae (Orchidaceae, Cranichideae) inferred from plastid and nuclear DNA sequences. Ann Bot 104: 403-416., 2011Salazar GA, Cabrera LI and Figueroa C. 2011. Molecular phylogenetics, floral convergence and systematics of Dichromanthus and Stenorrhynchos (Orchidaceae: Spiranthinae). Bot J Linn Soc 167: 1-18.). All these studies support the existence of four clades: “Stenorrhynchos Clade”, “Pelexia Clade”, “Eurystyles + LankesterellaClade” and “Spiranthes Clade”.

During fieldwork and the revision of some herbaria we verified the occurrence of two Spiranthinae genera: Lyroglossa Schltr. and Pteroglossa Schltr., currently included within the so-called “Stenorrhynchos Clade”, sensu Salazar et al. (2003)Salazar GA, Chase MW, Soto Arenas MA and Ingrouille M. 2003. Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences. Amer J Bot 90: 777-795.. To date, these taxa have not been formally cited for the orchid flora of Rio Grande do Sul (Rambo 1965Rambo B. 1965. Orchidaceae Riograndenses. Iheringia, Bot 13: 1-96., Pabst and Dungs 1975Pabst GFJ and Dungs F. 1975. Orchidaceae Brasilienses. Hildesheim: Kurt Schmersow, 408 p.). The purpose of the present contribution is thus to present descriptions, diagnostic features, illustrations, geographical and taxonomic notes for these taxa. In addition, an artificial key of the genera currently placed into the “StenorrhynchosClade” that are native to Rio Grande do Sul Brazilian State is provided. This paper is part of a series of taxonomic studies on the Orchidaceae native to Rio Grande do Sul (Buzatto et al. 2012Buzatto CR, Davies KL, Singer RB, Pires RS and Van Den Berg C. 2012. A comparative survey of floral characters in Capanemia Barb. Rodr. (Orchidaceae: Oncidiinae). Ann Bot 109: 135-144., 2014Buzatto CR, Sanguinetti A, Romero-González GA, Van Den Berg C and Singer RB. 2014. A taxonomic synopsis of the Brazilian Chloraeinae (Orchidaceae). Phytotaxa 158: 1-22.).

MATERIALS AND METHODS

Protologues were examined, as well as the herbaria that hold the type collections (AMES, B, BHCB, BM, CEN, CTES, F, G, GH, HAS, HB, HBG, HEPH, HUEFS, IBGE, ICN, INPA, IPA, K, K-L, M, MBM, NY, P, PACA, PEL, R, RB, S, SP, UB, UEC, VIC and W - acronyms according to Thiers 2009Thiers B. 2009. Index Herbariorum: a global directory of public herbaria and associated staff. New York Botanical Garden's Virtual Herbarium. Available in: <http://sweetgum.nybg.org/ih/>. Access in: 25 September 2009.
http://sweetgum.nybg.org/ih/... ) and relevant literature to Orchidaceae (Cogniaux 1895Cogniaux A. 1895. Fl Bras (Martius) Vol III, part 4., 1906Cogniaux A. 1906. Fl Bras (Martius) Vol III, part 6., Dressler 1993Dressler RL. 1993. Phylogeny and classification of the orchid family. Dioscorides Press, Portland Oregon, 316 p., Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). This paper follows the general orchid classification proposed by Chase et al. (2003). Orchid morphology terms were defined as per Dressler (1993)Dressler RL. 1993. Phylogeny and classification of the orchid family. Dioscorides Press, Portland Oregon, 316 p.and abbreviations for authorities for plant names follow Brummitt and Powell (1992)Brummitt RK and Powell CE. 1992. Authors of plant names. Royal Botanic Gardens, Kew, 732 p..

Taxonomic Treatment

1. Lyroglossa grisebachii (Cogn.) Schltr., Anexos Mem. Inst. Butantan, Secc. Bot. 1(2): 27-28. 1921 ≡ Spiranthes grisebachii Cogn., Fl. Brasil. 3(4): 207. 1893-1906. Figures 1and 3E–F.

Type: FRENCH GUIANA. sine loc., 1840, F.M.R. Leprieur s.n., no herbarium cited; lectotype designated by Szlachetko and Rutkowski (2008)Szlachetko DL and Rutkowski P. 2008. Classification of Spiranthinae, Stenorrhynchidinae and Cyclopogoninae. In: Rutkowski P, Szlachetko DL and Górniak M (Eds), Phylogeny and taxonomy of the subtribes Spiranthinae, Stenorrhynchidinae and Cyclopogoninae (Spirantheae, Orchidaceae) in Central and South America. Wydawnictwo Uniwersytetu Gdańskiego, p. 130-222.: G 168827, isolectotypes: P 345573; AMES (photo as G 168827).

Herb to 17.5 cm high, including the inflorescence. Roots fleshy, cylindrical, often stipitate, lanuginose. Leaves ca. 2.3 × 0.7 cm, 1–2, forming a basal rosette, usually absent during anthesis sometimes withered, sessile, acute, coriaceous, margin slightly translucent, bright to olive green, elliptic-lanceolate, gradually attenuate. Inflorescence ca. 3.5 cm long, 6 to 7-flowered, pubescent, scape terete, partially covered by 5 sheathing, acute bracts; raceme congested, most of them opened simultaneously; floral bracts ca. 2.5 cm long, prominent, green, glabrous, loosely concave, ovate, acuminate. Flowers resupinate, fleshy, whitish-green. Sepals densely pubescent outside. Dorsal sepal ca. 6.1 × 2.3 mm, slightly spreading, adherent to the lateral sepals on its proximal part, densely pubescent externally, lanceolate, recurved at the acute apex, the margins entire. Lateral sepalsca. 6.4 × 2.8 mm, slightly to strongly patent, shortly connate at base forming a small, conical, rounded spur of ca. 5 mm long, densely pubescent outside, ovate-lanceolate, recurved at apex, acute, margins entire. Petals ca. 5.8 × 2.2 mm, glabrous, with 5 conspicuous green veins, ovate, acute, margins entire. Labellum ca. 7.2 × 3.5 cm, three-lobed, blade pubescent outside, often papillose near the base, adnate at base with the lateral sepals in the spur, long-clawed and narrowly channeled below the middle; apical lobe deflexed, obtuse to retuse. Column ca. 7.2 x 3.1 mm, ca. 2.2 mm height, semiterete, stout, pubescent, the base extended into a long column-foot, the membranaceous clinandrium margins are rounded and enclose the basal portion of the anther; the anther is thick, massive, ovate, acuminate, with filament adnate; pollinarium ca. 2.6 × 1.1 mm, 0.7 mm height, formed by 2 deeply bipartite, granular pollinia, narrowly clavate, with ventral, apical, oval, grey viscidium; rostellum remnant ca. 0.8 mm long, narrowly triangular, stiff, obscurely tridentate at the portion originally covered by the viscidium; stigma bilobed toward the base. Ovary ca. 7.2 mm long, 3.1 mm diameter near the apex, densely pubescent up to pedicel. Capsule ellipsoid. Seeds minute and fusiform.

Notes: Lyroglossa grisebachii is the type-species of the genus (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). Lyroglossa shares some floral features with Pteroglossa, such as the short, ventrally channelled column, narrowly triangular rostellum, concave anther and marginal, completely adnate nectar glands (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). Based on morphological features, Salazar (2003)Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278. tentatively placed it in the so-called “Stenorrhynchos Clade”. However, its relationships are still not sustained by a molecular phylogeny (Chase et al. 2003, Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.).

Distribution: Lyroglossa grisebachii is currently known in the Atlantic Rain Forest and Cerrado Biomes, in Minas Gerais, Paraná, São Paulo, Goiás, Distrito Federal and Mato Grosso.

In Rio Grande do Sul, this species dwells in wet grassy formations (“campos”) surrounding Atlantic forests. Additionally, L. grisebachii occurs in grasslands within the Pampa Biome, growing in slightly humid soils.

Batista et al. (2012)Batista JAN, Menini Neto L and Alves AA. 2012. Three new species, four new records and an updated checklist of Habenaria (Orchidaceae) from Rio Grande do Sul, Brazil. Nordic J Bot 30: 1-14., mentioned the presence of L. grisebachii in Rio Grande do Sul without providing a voucher. We herein formally record L. grisebachii for the State of Rio Grande do Sul, therefore extending the austral limit of this genus.

Specimens examined: BRAZIL. Rio Grande do Sul: Cachoeira do Sul, December 1986, fl., M. Sobral et al. 5367(ICN); São José dos Ausentes, 23 January 2010, fl., C.R. Buzatto 606 & R.B. Singer (ICN); 2 February 2008, fl., J.A.N. Batista 2492 (BHCB).

Additional specimens examined: BRAZIL. Distrito Federal: Brasília, 14 December 1989, fl., J.A.N. Batista 37(HUEFS). Goiás: Alto Paraíso de Goiás, 9 February 2004, fl., C. van den Berg 1226 (HUEFS); Cavalcante, 1 January 1999, fl., J.A.N. Batista 824 (HUFU, UEC); Pirenópolis, 8 December 1987, fl., L.C. Bernacci 19970(UEC); sine loc., 21 December 1968, fl., Graziela et al. 517 (HB). Mato Grosso: Chapada dos Guimarães, 14 October 1973, fl., G.T. Prance 18955A(INPA). Minas Gerais: Minduri, 5 November 1999, fl., A.O. Simões 952 (UEC); Tiradentes, 6 December 1983, fl., H.F. Leitão Filho 15266 (UEC). Paraná: Curitiba, 5 January 1965, fl., L.T. Dombrowski & Y. Saito 1283b (MBM); Sengés, 19 September 1975, fl., G. Hatschbach 37112 (MBM). São Paulo: sine loc., 10 October 1917, fl., A. Gehrt 1041 (NY).

2. Pteroglossa macrantha (Rchb. f) Schltr., Beih. Bot. Centralbl. 37(2): 450. 1920 - Spiranthes macrantha Rchb. f., Linnaea 19: 378. 1846 ≡ Gyrostachys macrantha (Rchb. f.) Kuntze, Revis. Gen. Pl. 2: 664. 1891 ≡ Stenorrhynchos macranthum(Rchb. f.) Cogn., Fl. Bras. 3(4): 176. 1895. Figures 2 and 3A–D.

Type: BRAZIL: Minas Gerais, sine loc., 1838, M. Claussen 391 (P 345647).

Spiranthes albescens Barb. Rodr., Gen. Sp. Orchid. 1: 186. 1877 ≡ Stenorrhynchos albescentis (Barb. Rodr.) Barb. Rodr., Gen. Sp. Orchid. 1 (Index): X. 1877.

Type: BRAZIL. “Hab. Dans la Serra de Caldas, Minas Geraes”, s.d., J. Barbosa Rodrigues s.n. [lost], lectotype designated by Buzatto et al. (2013)Buzatto CR, Singer RB, Romero-González GA, Van Den Berg C and Salazar GA. 2013. Typifications and taxonomic notes in species of Brazilian Goodyerinae and Spiranthinae (Orchidaceae) described by José Vellozo and Barbosa Rodrigues. Taxon 63: 609-621..

Herb to 45 cm high, including the inflorescence. Roots fleshy, cylindrical, often stipitate, lanuginose. Leaves ca. 20–25 × 5–8 cm, 7–8, forming a basal rosette, usually present during anthesis sometimes withered, sessile, acute, coriaceous, margin translucent, light green, lanceolate, external leaves slightly attenuate at base, the inner leaves more attenuate. Inflorescence ca. 14 cm long, with ca. 15 flowers, pubescent, scape terete, partially covered by 6–7 tubular, acute bracts; raceme congested, most of them opened simultaneously; floral bracts ca. 4.5–6 cm long, prominent, green, glabrous, loosely concave, ovate, acuminate. Flowers resupinate, fleshy, greenish-white with yellow veins. Sepals densely pubescent outside. Dorsal sepal ca. 26 × 4 mm, slightly spreading, adherent to the lateral sepals on its proximal one-thirds, densely pubescent outside, lanceolate, acuminate, the margins entire. Lateral sepals 36 × 6 mm, forming a shortly conical, rounded, prominent spur of ca. 15 mm long, densely pubescent outside, elliptic-lanceolate, falciform, acuminate, margins entire. Petals ca. 29 × 5 mm, glabrous, bearing 3 conspicuous veins, fusiform, acuminate, margins entire. Labellum ca. 30 × 9 cm, three-lobed, blade pubescent outside, glabrous near the apex, adnate at base with the lateral sepals in the spur, long-clawed and narrowly channelled below the middle; the lateral lobes semi-orbicular, the mid-lobe ovate to obovate-spatulate, acute to rounded. Column ca. 15 × 10 mm, 5 mm height, hemi-terete, stout, pubescent, the base extended into a long column foot, the membranaceous clinandrium margins are enclosed with basal portion of the anther; the anther is thick, massive, ovate, long-acute, with filament completely adnate; pollinarium 2 × 3–4 mm, 3 mm height, formed by 2 deeply bipartite, granular pollinia, narrowly clavate, with ventral-apical, oval, grey viscidium; rostellum remnant ca. 3 mm long, narrowly triangular, stiff, obscurely tridentate at the portion originally covered by the viscidium; stigma slightly bilobed toward its base. Ovary ca. 20 mm long, 5 mm diameter near the apex, densely pubescent. Capsule ellipsoid. Seedsminute and fusiform.

Notes: Pteroglossa macrantha is the type-species of the genus (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). It is worth noticing here that leaf morphology of the specimens examined do not agree with the description provided by Salazar (2003)Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278., who described the leaves of this species as being oblanceolate and long petiolate. The specimens we studied have leaves. Salazar's description of leaves fits very well the description of two other species, namely P. roseoalba(Rchb.f) Salazar & M.W.Chase and P. glazoviana(Cogn.) Garay. However, the attenuated leaves of P. macrantha (Figure 3A–B) are considerably different from this description (see species description) and are remarkably similar to those of robust specimens of Skeptrostachys Garay.

Pteroglossa comprises about ten species distributed from Mexico to Costa Rica and from Colombia to Argentina (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). In Brazil, Pteroglossa occurs mainly in the Atlantic Rain Forest Biome, in the states of Minas Gerais, Paraná, São Paulo, Rio de Janeiro and Espírito Santo (Salazar 2003Salazar GA. 2003. Subtribe Spiranthinae. In: Pridgeon AM et al. (Eds), Genera Orchidacearum vol. 3: Orchidoideae part 2, Vanilloideae. Oxford University Press, Oxford, p. 164-278.). It shares a number of morphological features (e.g. labellum and column shape; Figure 3D) with other members of the “Stenorrhynchos Clade”, mainly with Eltroplectris Raf., and this seems to indicate a closer relationship between these and other genera in this clade. Recent molecular studies (Salazar et al. 2011Salazar GA, Cabrera LI and Figueroa C. 2011. Molecular phylogenetics, floral convergence and systematics of Dichromanthus and Stenorrhynchos (Orchidaceae: Spiranthinae). Bot J Linn Soc 167: 1-18.) support such a relationship and have indicated that Pteroglossa is inserted within the “Stenorrhynchos Clade”, and is closely related to Sacoila Raf., Mesadenella Pabst & Garay and Eltroplectris.

Distribution: Pteroglossa macranthaoccurs mainly at the Cerrado Biome (especially, Goiás, Distrito Federal and Mato Grosso). After an extensive revision of the literature and the herbarium material available, this species is recorded for the first time to the State of Rio Grande do Sul. This new record makes Rio Grande do Sul the austral limit of this genus.

Specimens examined: BRAZIL. Rio Grande do Sul: Jaquirana, 5 January 2013, C.R. Buzatto 899 & S.A.L. Bordignon (ICN); São Francisco de Paula, 23 January 2007, fl., S.A.L. Bordignon s.n. (ICN 174065).

Additional specimens examined: BRAZIL. Distrito Federal: Brasília, s.d., fl., F. Sello s.n. (HBG 506820). Goiás: Alvorada do Norte, 10 October 1976, fl., G. Hatschbach 39113 (MBM); sine loc., 26 October 1964, fl., H.S. Irwin 7371 (NY). Mato Grosso: Coxipó, December 1978, fl., J.G.A. Lima 860 (HB); Lago São Léo, 11 October 1968, fl., A. Lima 438–68(IPA); Xavantina, 12 October 1967, fl., A. Argent & J. Ramos 6735 (HB); sine loc., 10 October 1964, fl., H.S. Irwin 6725 (NY); sine loc., s.d., fl., Willian s.n. (HB 75708). Minas Gerais: Caldas, 20 October 1866, fl., A.F. Regnell III1198 (S); Ituiutaba, 10 November 1948, fl., A. Macedo 1342 (MBM, NY, RB); Paracatú, 21 October 1989, fl., A.H. Salles et al. 1411 (HEPH); sine loc., 1838, fl., P. Claussen 391(P). Rio de Janeiro: Santo Antônio de Imbé, April 1932, fl., A.C. Brade & S. Lima 11734 (HB). Tocantins: Aparecida do Rio Negro, 1 November 2001, fl., C.E. Rodrigues Jr. 1514 (HEPH).

ACKNOWLEDGMENTS

We thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq project 470353/2011-2) for financial support. CRB acknowledges the study grant (project 1099/2010) received from Coordenação de Aperfeiçoamento do Pessoal de Nível Superior (CAPES) and Pró-Reitoria de Pós-Graduação (PROPG/UFRGS, Edital 001/2011) for financial support.

REFERENCES

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