Sisyrinchium sectiandrum C.D.Inácio & L.Eggers, 2018

Inácio, Camila Dellanhese, Chauveau, Olivier & Eggers, Lilian, 2018, Three new species of Sisyrinchium (Iridaceae) from Campos of South America, Phytotaxa 361 (2), pp. 198-210 : 207-208

Sisyrinchium sectiandrum C.D.Inácio & L.Eggers , sp. nov. ( Figs. 1B and 6 )

Sisyrinchium sectiandrum resembles S. fiebrigii , but differs by the staminal column basally connate for less than 1 mm with sparse or no trichomes.

Type: — BRAZIL. Paraná: Sengés, Serra do Mocambo, 8 October 1971 (fl, fr), G. Hatschbach 27163 ( MBM!).

Perennial herb, erect, (28–) 39–70 cm tall. Rhizome inconspicuous, with slender and fibrous roots. Basal leaves, erect, terete, 16.8–34 × 0.08–0.12 cm, glabrous, acute, sometimes with conspicuous sheaths 5–6.5(–9.5) cm long and rudimentary lamina, 1.5–13 cm long. Flowering stem simple, erect, terete, 26–68 × 0.1–0.17 cm, with a terminal bract 1.4–17.5 cm long, proximally enlarged and membranaceous for 5.4–10.3(–16.1) mm. Synflorescence fasciculiform, 7–20 riphidia, congested at the base of the terminal bract and an opposite bract, 4.2–8.4 mm long, cuspidate to aristate, awn 1.2–7(–12.2) mm, margin membranaceous of 0.5–0.8 mm wide. Rhipidium 3–4 flowers, subsessile, peduncle 0.5–2.5 mm long. Spathes bivalved, lower valve 5.5–8.9 × 1.5 mm, upper 6–10.5 × 1–1.3 mm, acute to cuspidate, margin membranous for 0.5–0.7 mm. Pedicel longer than spathes, 7–15 mm long, with sparse translucent trichomes. Perigone disk shaped, yellow, 8.5–12 mm diameter (fresh and dried flowers of exsiccates). Tepals subequal, (4.1–)4.8– 6.4 × (1.8–) 2.3–3 mm, elliptic to oblanceolate, apiculate to emarginate-apiculate, with three vinaceous veins at adaxial side and reddish surface with sparse trichomes at abaxial side. Filaments yellow, basally connate for (0 −) 0.3 − 1.2 mm, then free for 0.8 − 2 mm, ascending to patent, with or without sparse trichomes at the base. Anthers yellow, basifixed, 0.8 − 1.3(− 1.5) mm long. Ovary globose, 1–1.4(− 1.6) mm long and wide, pilose. Style yellow, entire, 2.5–3.1 mm long, with stigmatic region displaced above the anthers. Capsule globose, 2.4–4.3 × 2.1–4.3 mm, brown, with sparse trichomes.

Distribution and Habitat:— Sisyrinchium sectiandrum was collected in the northeast region of the state of Paraná, Brazil ( Fig. 3 ), in the municipalities of Carambeí, Jaguariaíva, Piraí do Sul, Sengés and Tibagi, in the Atlantic Forest Biome. The elevation records range from 1127 to 1254 m a.s.l. The species occurs in grasslands marked by rocky outcrops and populations usually consist of sparse individuals.

Phenology: —Flowering and fruiting from August to November.

Conservation Status:—According to the IUCN Red List guidelines ( IUCN 2016), the species is considered to be Endangered (EN), with subcriteria B1(a) and (b)iii: continuing decline of extent of occurrence and a decline of quality of habitat due to loss or reduction of the natural distribution by silvicultural and agricultural expansion.

Etymology:—The species is named in reference to the predominantly free filaments which is a striking trait in similar taxa with terete leaves.

Paratypes:— BRAZIL. Paraná: Carambeí, Alto Carambeí, estrada para rio São João , 2 November 2013 (fl), M. E. Engels & E. D. Lozano 1954 ( MBM!) ; Jaguariaíva, PR 151, Km 228, antes do Rio Diamante , cerca de 12 km antes de Jaguariaíva , 1125 m, 24°21’16’’S, 49°48’21.1”W, 31 October 2017 (fl, fr), L. Eggers et al. 1042 ( ICN!) ; Jaguariaíva, PR 151 aproximadamente Km 229, 1130 m, 24°21’18.5’’S, 49°48’22.1”W, 1 November 2014 (fl), C. D. Inácio et al. 265 ( ICN!, MBM!, CTES!, RB!) ; Jaguariaíva, PR 151 em direção a Ponta Grossa, próximo a Jaguariaíva , 1127 m, 24°21’17.4”S, 49°48’22.1”W, 27 October 2008 (fl, fr), L. Eggers & T. T. Souza-Chies 349 ( ICN!) ; Jaguariaíva, Parque Estadual do Cerrado, margem do rio Santo Antonio , 26 August 2000 (fl), V. Linsingen 219 ( MBM!) ; Piraí do Sul, PR 090 (estrada secundária de Piraí do Sul a Ventania ), aproximadamente Km 156.5, 24°28’37.8” S, 50°00’16.5” W, 1254 m, 20 November 2010 (fl), L. Eggers & T. T. Souza-Chies 630 ( ICN!) ; Piraí do Sul, PR 090, Km 162.2, 24°26’37.4”S, 50°01’43,2”W, 1180 m, 21 November 2010 (fl), L. Eggers & T. T. Souza-Chies 645 ( ICN!) ; Tibagi, Rio Tibagi , 6 September 1966 (fl), G. Hatschbach & O. Guimarães 14689 ( MBM!, NY!) ; Tibagi, Rio Tibagi , margem direita, próximo a ponte, 7 October 1994 (fl, fr), D. C. Lemos et al. s.n. ( FUEL 14527 !) ; Tibagi, Guaterlá, sítio São Sebastião , propriedade da Sra. Júlia , 21 September 2013 (fl), E. L. Siqueira et al. 719 ( UFMT!) .

Taxonomic relationships: —The new species belongs to S. sect. Cephalanthum Baker (sensu Inácio et al. 2017) and resembles other taxa with terete leaves and scapes. However, staminal column is very particular, exhibiting connate filaments solely at the base, with half or more of the length free. Plants with terete leaves and full-length connected filaments usually present purple or vinaceous flowers, such as South Brazilian S. purpurellum Ravenna (2002: 24) and S. pendulum Ravenna (2002: 23) . Plants with yellow flowers and terete floriferous stems occur mainly in Central-West Brazil, such as S. luzula Klotzsch ex Klatt (1861 –1862: 89), and S. burchelii Baker (1892: 57) , which, however, present leaves with rudimentary lamina. Sisyrinchium fiebrigii Johnston (1938: 384) , described for Paraguay but distributed in South Brazilian states of Rio Grande do Sul and Paraná as well, is the most similar taxon of S. sectiandrum in vegetative state, since it has conspicuous leaf lamina. Both species are also similar in plant height, leaf lamina length and width, floriferous stem length and width, peduncle length, valves length and width, pedicel length and fruit length and width. Sisyrinchium fiebrigii differs from S. sectiandrum by the long staminal column with filaments connate almost to the top, free for just 0.1 to 0.4 mm, bearing oil-trichomes (elaiophores) for 0.4 to 0.5 mm long, as compared to the smaller column with free filaments for 0.8–1.7(–2) mm, with no trichomes or with a 0.2 mm extension of trichomes in S. sectiandrum ( Table 3).

Figures

FIGURE 1. Habit. A. Sisyrinchium pampeanum C.D.Inácio & L.Eggers. From C.D. Inácio et al. 147 (ICN). B. Sisyrinchium sectiandrum C.D.Inácio & L.Eggers. From G. Hatschbach 27163 (MBM). Scale bars: 5 cm. Drawings by Anelise Scherer.

FIGURE 3. Distribution map of Sisyrinchium pampeanum (squares), S. diversicarpum (circles) and S. sectiandrum (triangles) in Southern Brazil and Uruguay border.

FIGURE 6. Sisyrinchium sectiandrum C.D.Inácio & L.Eggers. A. Habit. B. Synflorescence. C. Androgynoecium showing free filaments apically. D. Habitat in disturbed grassland, with Pinus sp. in the background, Paraná, Brazil. From: L. Eggers et al. 1042 (ICN)