Sisyrinchium antemeridianum Aita & L.Eggers, 2013

Aita, Adriana M., Chauveau, Olivier, Souza-Chies, Tatiana T. & Eggers, Lilian, 2013, Two new species of Sisyrinchium (Iridaceae) from Subtropical Highland Grasslands of Southern Brazil, Phytotaxa 88 (1), pp. 9-18 : 10-11

Sisyrinchium antemeridianum Aita & L.Eggers , sp. nov. ( Figs. 1 and 3 A–D )

A S. decumbenti floribus majoribus; tepalis 9.8–12 mm longis, 2.8–5 mm latis; filamentis 2 mm connatis; stylis 2–2.2 mm longis, stylorum ramis 2–3 mm longis; ovario majore, 2–3 mm longo, 1.5–2 mm lato distincto est.

Type:— BRAZIL. Rio Grande do Sul: São Francisco de Paula , 25 November 2005, L . Eggers & T. T . Souza-Chies 151 (holotype ICN!) .

Perennial herb, up to 23 cm. Rhizome conspicuous, slender, fibrous, with coarse roots. Leaves basal, equitant, erect to slightly curved, emerald-green, linear-ensiform, 5–16 × 0.1–0.3 cm, glabrous, with one or two more prominent veins, apex acute, margins thickened. Scape simple, erect to slightly arcuate, narrowly winged, 7.7–24.5 × 0.1–0.2 cm, with a terminal bract. Bract with basally scarious margin, 1.3–4.3 cm long. Inflorescence of one or more rhipidia. Rhipidia mostly sessile, occasionally pedunculate, enclosed by spathes, with 1–4(–8) flowers, opening one at a time. Spathes acute, margin scarious (11.7–)12.5–20(–21.4) mm long. Pedicel glabrous, usually longer than spathes, (9.8–)13.8–22(–24) mm long. Flowers yellow. Tepals subequal, spreading, oblanceolate, acute to acuminate, adaxial side with central vein strongly marked, abaxial side with central and lateral veins (2–3 pairs) dark coloured, 9.3–12 × 2.8–5 mm. Filaments yellow, glabrous, basally connate for 2 mm, then free for 1.5–2 mm, ascending to patent. Anthers yellow, dorsifixed, incurved at dehiscence, 3–3.5 mm long. Ovary glabrous, 2–3 × 1.5–2 mm. Style yellow, glabrous, 2–2.2 mm long, style arms alternate to the stamens, ascending to patent, 2–3 mm long, stigma capitate to truncate, papillate. Capsules globose, dark brown, 3–5 × 2.5–4.3 mm.

Distribution and Habitat:— Sisyrinchium antemeridianum was collected in Southern Brazil in the states of Santa Catarina and Rio Grande do Sul ( Fig. 4 ), in grassland vegetation of high elevation, usually above 900 m a.s.l. In some areas, it grows among grasses but occasionally behaves like a prostrate grass species and completely covers the ground. The range of the species falls within the Atlantic Forest Biome.

Phenology: —Flowering and fruiting from October to March.

Conservation Status: —According to the IUCN Red List guidelines ( IUCN 2001), the species can be considered as Nearly Threatened (NT) but may qualify for a higher threat category in the near future, mainly because of the steady decline of its habitat through expansion of agriculture in the Subtropical Highland Grasslands.

Etymology: —The species name is a reference to the morning opening flowers, since this is not a common feature for species belonging to the sect. Hydastylus , which usually open flowers in the afternoon.

Additional specimens examined (paratypes):— BRAZIL. Rio Grande do Sul: Bom Jesus , São José dos Ausentes, 8 February 1988 (fr), N . Silveira & D. Farias Filho 5193 ( HAS!) ; Cambará do Sul em direção a São Francisco de Paula , February 1948 (fl, fr), B . Rambo ( PACA 36605 !) ; Cambará do Sul, Fortaleza , 1 April 1982, J . Amattos & N . Silveira 23498 ( HAS!) ; Cambará do Sul, Itaimbézinho , próximo ao canyon, 11 March 1988 (fl), N . Silveira 7360 ( HAS!) ; Cambará do Sul, Fortaleza , 12 November 1993 (fl, fr), N . Silveira 12190 ( HAS!) ; Cambará do Sul, Fortaleza , 12 January 1994 (fl), N . Silveira 10426 ( HAS!) ; Cambará do Sul, Parque Nacional dos Aparados da Serra , December 2004 (fl, fr), K. T . Bottega Kerber 73 ( PACA!) ; Cambará do Sul, Parque Nacional de Aparados da Serra , 8 November 2006 (fl, fr), J . Lovo , I . Cordeiro , L . Temponi & M . Sobral 195 ( SPF!) ; Cambará do Sul , RS 20, km 134, 30 November 2006 (fl, fr), L . Eggers & T. T . Souza-Chies 204 ( ICN!) ; Cambará do Sul, 1,005 m, 16 March 2011 (fr), A . Aita & E . Pasini 35 ( ICN!); Porto Alegre, coletada da coleção viva do Jardim Botânico, planta originalmente trazida de Rio Grande do Sul, São José dos Ausentes, Serra da Rocinha , área da plataforma de vôo livre, November 2008 (fr), L . Eggers ( ICN 190710 !); São Francisco de Paula, Itaimbezinho , 5 November 1951 (fl), B . Rambo ( PACA 51376 !); São Francisco de Paula, Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata), without date (fl, fr), A . Fidelis ( ICN 190711 !); São Francisco de Paula, Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata ), without date (fr), F. J. M . Caporal ( ICN 190712 !); São Francisco de Paula, Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata), November 1996 (fl, fr), Wolfgang Maier 2865 ( ICN!); São Francisco de Paula , Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró- Mata), 24 November 1997 (fl, fr), Birgit Harter 2915 ( ICN!); São Francisco de Paula , Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata), 24 November 1997 (fl, fr), Birgit Harter 2916 ( ICN!); São Francisco de Paula , Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata), 28 November 1998 (fl), B . Truylio & S. L . Candido 3286 ( ICN!); São Francisco de Paula, Centro de Pesquisas e Conservação da Natureza Pró-Mata ( CPCN Pró-Mata), 06 January 2004 (fl), L . Eggers & T. T . Souza-Chies 47 ( ICN!); São Francisco de Paula, RS 20, antes da entrada do Veraneio Hampel , 30 November 2006 (fl, fr), L . Eggers & T. T . Souza-Chies 200 ( ICN!); São Francisco de Paula, RS 235, próximo a entrada do Veraneio Hampel , 10 October 2007, L . Eggers & T. T . Souza-Chies 213 ( ICN!); São Francisco de Paula, RS 20, após Rio do Pinto , 20 October 2006 (fl, fr), L . Eggers & T. T . Souza-Chies 168 ( ICN!); São Francisco de Paula, RS 20, km 100, passando a ponte sobre Rio do Pinto , October 2011 (fl, fr), T. L. S . Alves 121 ( ICN!); São Francisco de Paula , 998 m, 15 March 2011 (fl, fr), A . Aita & E . Pasini 30 ( ICN!); São Francisco de Paula, acesso em direção ao Canion Josafá , 946 m, 10 November 2011 (fl, fr), T. L. S . Alves 135 ( ICN!); São José dos Ausentes, Serra da Rocinha em direção a Bom Jesus , 3 February 1953 (fr), B . Rambo ( PACA 53837 !) ; Santa Catarina: Bom Jardim da Serra , 1412 m a.s.l., 29 November 2011 (fl), A . Aita & E . Pasini 131 ( ICN!) .

This species was first collected by Rambo in February of 1948, and determined as S. nidulare (Handel- Mazzetti 1908: 216) Johnston (1938: 383). It was also identified as S. palmifolium , S. avenaceum Klatt (1861 –1862: 373) and S. binervatum . Quite common in the Subtropical Highland Grasslands, S. antemeridianum is not encountered beyond the limits of this biome. Sisyrinchium antemeridianum is morphologically similar to the less known S. binervatum and S. decumbens . Sisyrinchium binervatum is a species endemic to Minas Gerais, regarded as rare in damp areas, particularly near streams, at 2300 m a.s.l. The binervate leaves are diagnostic for this species. There is just one cited material for it at the GFJP Herbarium ( Ravenna 2000). Comparison with original description of S. binervatum reveals that S. antemeridianum has stouter habit and very short rhizome. Furthermore, in S. binervatum the flowers are not completely exserted from the spathes and differ also in measurements of the stamens ( Table 1). Sisyrinchium decumbens was found in the Highland Grasslands of Rio Grande do Sul and Santa Catarina, as well as the new species presently described. However, Herbarium studies and collection trips in the same area have failed to identify any sample of S. decumbens among the plants examined. Ravenna (2002) reported that the latter species looks like S. binervatum , with a tendency to display leaves and scapes obliquely. The collected material cited in the protologue consists of two samples, the holotype, with few isotypes, and one paratype. The holotype is kept in the private Herbarium of Ravenna with the isotypes and none of them is available for analysis, and the paratype, which was supposed to be at MBM Herbarium, is missing. Therefore, it was not possible to compare material directly. Anyway, measurements of S. antemeridianum checked against the original description of S. decumbens reveals that the new species differs in the size of the stamens: the filaments are connate on 2 mm (against 0.8 mm in S. decumbens ) and the anthers are 3–3.5 mm long (against 1.9–2 mm in S. decumbens ). Sisyrinchium antemeridianum is also a taller plant (up to 23 cm against 12–14 cm) and the tepals are larger (9.8–12 × 2.8–5 mm against 8–9 × 2.5–3 mm) ( Table 1).

Figures

FIGURE 1. Sisyrinchium antemeridianum Aita & L.Eggers. A. Habit B. Sessile rhipidium and bract C. Pedunculate rhipidia and bract D. Flower in frontal view. From L. Eggers & T.T. Souza-Chies 151(ICN!), drawings by Edson Luís de Carvalho Soares.

FIGURE 3. Sisyrinchium antemeridianum Aita & L.Eggers. A. Habit. B. Inflorescence and tepals in abaxial side. C. Flowers and fruits. D. Habitat. Sisyrinchium flabellatum Aita & L.Eggers. E. Rhipidium, flower and fruits. F. Flowers. G. Habit. H. Habitat. I. Inflorescences.

FIGURE 4. Distribution map of Sisyrinchium antemeridianum (circles) and S. flabellatum (star) in Southern Brazil.