Cypella altouruguaya Chauveau & L.Eggers, 2014

Chauveau, Olivier, Pastori, Tamara, Souza-Chies, Tatiana T. & Eggers, Lilian, 2014, Overlooked diversity in Brazilian Cypella (Iridaceae, Iridoideae): four new taxa from the Río de la Plata grasslands, Phytotaxa 174 (1), pp. 25-42 : 26-28

Cypella altouruguaya Chauveau & L.Eggers , sp. nov. ( Figs. 1A and 2 )

Cypella altouruguaya differs from two closely related species with similar yellow flowers, C. armosa and C. pabstiana , by the cuneate proximal half of the inner tepals (vs. unguiculate). It reminds C. armosa in flower size, but differs by its wider outer tepals, slightly retuse connective apex, adaxial crests not twisted basally and longer abaxial crests. The gross morphology of C. altouruguaya comes close to C. pabstiana , which is distinguished by its smaller flower, longer and totally free filaments, longer anthers and slightly excurrent connective apex.

Type: — BRAZIL. Rio Grande do Sul : Rio Grande do Sul: Trindade do Sul, estrada Trindade do Sul - Pinhalzinho , 610 m, 03 December 2011 (fl, fr), T. B. Guimarães & L. Dal Ri 6 A (holotype, ICN!)

Perennial herb, up to (32–) 39–70 cm high above the soil, underground stem up to (3.5–)4.8–8.3(–8.7) cm long. Bulb ovoid, outer cataphylls dark brown, 14–15(–16.8) × (8–) 12–15 mm, prolonged in a collar up to (1.8–)3.5–5 (–5.6) cm. Basal leaves green at anthesis 1–3(–4), blades linear-attenuate, plicate, (16.8–)22.5–42(–47) × (0.15–)0.3–0.45(–0.7) cm. Flowering stem cylindrical, (28–) 40–63.4 cm long, proximally foliate (one reduced cauline leaf, rarely absent), then bracteose; first internode (4.2–)10–17.2(–19.5) cm long; cauline leaf (11–)16.1–32.7(–39) × (0.15–)0.3–0.7(– 0.75) cm. Synflorescence cymosely branched, branches usually 2(–3), each subtending 2–4 pedunculate inflorescences arising from the same point, peduncles (1.0–)3–10.5(–11.5) cm long. Inflorescence one-flowered (rhipidium like); spathes herbaceous, bivalved, lower valve (2–) 2.4–3.9 cm long, the upper (3.5–)4–6.3(–6.7) cm long, both with narrow membranous edges. Pedicel filiform, generally shorter than the upper valve with the ovary usually partly to sometimes entirely exserted. Flowers predominantly bright yellow, 45–55 mm diameter. Tepals unequal, shortly fused proximally for 0.5 mm. Outer tepals pandurate, (32–)37–42(–46) × (21–)24–31(–33) mm; the proximal part concave, pale yellow to bright yellow, slightly translucent, broadly marked with a red-brown irregular spot at the base, the distal edge of the concave part sparsely marked by an area of yellow glandular trichomes along the central vein; the distal part reclinate, bright yellow, obovate, retuse and acuminate. Inner tepals reduced, assurgent proximally, then incurved and abruptly reclinate distally, (10–)10.5–12.5(–13) × (8.5–)9–12(–13) mm; the proximal half cuneate, not unguiculate, bright yellow, broadly streaked with red-brown; the distal half bright yellow, longitudinally depressed, except at the distal end, with a dense oblong orange-yellow area of oil-producing trichomes (elaiophore) marked with red-brown spots, the lateral sides firmly revolute, striated transversely with red-brown, the apex acute, spotted with red-brown. Filaments free, erecto-patent and abruptly incurved at the distal end, whitish to whitish-yellow, obclavate, thick, 0.8– 0.9 mm wide at mid-length, striated with purple on the inflated base, rarely on the whole length, 3–3.5(–4) mm long. Anthers oblong, 6–7(–7.9) × 1.4–1.8(–2) mm, adnate to the style arms for half of the length; connective apically slightly retuse, whitish-yellow to yellow towards the distal end, 0.8–1.2(–1.5) mm wide, usually covered with a viscous and transparent secretion; locules black; pollen dark yellow-green. Ovary subclavate, (6–)7–9.5(–11) × 2–2.9(–3.1) mm. Style whitish to yellow, 5–6 (–6.2) mm long. Style arms bright yellow, conduplicate, 5–6.5(–7) mm long; crests at the apex, bright yellow, adaxial crest 2, erect, falcate inwards, (3.5–)4–6(–6.5) mm long, abaxial crest triangular, lobed, (1–)1.3–2.6(–3) mm long; stigmatic surfaces transverse, 2, on each side at the base of the abaxial crest, bright yellow, (1.1–)1.2–1.6(–1.8) mm long. Capsule obovate-truncate, (10–)11.7–16.8(–21.8) × (3–)3.5–5(–5.4) mm. Seeds obconical, triangular in adaxial view, sharply angulate, epidermis verrucose areolate, 1.3–1.5 mm long.

Distribution and Habitat:— Cypella altouruguaya was collected in the northern part of the state of Rio Grande do Sul, Southern Brazil ( Fig. 3 ), in herbaceous vegetation along roadsides and in contiguous grasslands. The elevation records range from 592 to 615 m. The geographical distribution of the species is markedly reduced, but the populations are dense and consist of numerous individuals. The range of the species falls within the Subtropical Highland Grasslands ( Iganci et al. 2011), included in the Atlantic Forest biome.

Phenology: —Flowering and fruiting from August to December.

Conservation Status: —According to the IUCN Red List guidelines ( IUCN 2001), the species is considered Critically Endangered (CR), with subcriteria B1 (a) and (biii): continuing decline of extent of occurrence and a decline of quality of habitat due to agricultural expansion.

Etymology: —Named after the Alto Uruguai, a physiographic area bounded by the Uruguai and Ijuí rivers where the species was encountered. This region lies in the northern part of Rio Grande do Sul.

Additional specimens examined (paratypes): — BRAZIL. Rio Grande do Sul : Trindade do Sul, estrada secundária entre Trindade do Sul e Rodeio Bonito , beira de estrada, 615 m, 18 August 2012 (fl), L . Eggers & O . Chauveau 716 ( ICN!) ; Trindade do Sul, estrada secundária entre Trindade do Sul e Rodeio Bonito , campo baixo, 592 m, 5 December 2013 (fl, fr), L . Eggers & O . Chauveau 884 ( MBM!) .

Taxonomic relationships: —We first studied one herbarium specimen of the new species collected in 2011 and kept at ICN; thereafter, further specimens were obtained by ourselves at the type locality in August 2012. Only one plant had flowers at this time of the year, but bulbs of similar plants were collected from a large population and cultivated for identification, illustration and measurements. Additional field observations were conducted in 2013. The species is here compared with two species of Cypella with yellow flowers: C. armosa Ravenna (1981a: 20) and C. pabstiana Ravenna (1981a: 18) . Cypella armosa is readily distinguished from the new species by the overall shape of the flower, marked by the laxly hanging outer tepals, and its long and twisted adaxial crests. Cypella pabstiana may be more easily confused with C. altouruguaya , and detailed observations of the stamens are needed to discriminate between the two species. In C. pabstiana , the filaments are connate for more than two-thirds of their length and both filaments and anthers are distinctly shorter. The character states retained to compare and separate the different species are presented in Table 1.

Figures

FIGURE 1. Habits of new species of Cypella. A. C. altouruguaya Chauveau & L.Eggers. From T.B. Guimarães & L. Dal Ri 6 (ICN!) B. C. amplimaculata Chauveau & L.Eggers. From A.M. Aita 49 (ICN!), drawings by Anelise Scherer.

FIGURE 2. Cypella altouruguaya Chauveau & L.Eggers. A–C. Flower. A. apical view B. lateral view C. basal view D–F. Inner tepal D. adaxial view E. abaxial view F. lateral view G. Ovary H. Stamens and style in lateral view I. Style crests and stigmatic replicatures. From L. Eggers & O. Chauveau 716 (ICN!).

FIGURE 3. Distribution map of Cypella altouruguaya (triangle inside circle), C. hauthalii subsp. minuticristata (star inside circle) and C. rivularis (rhombus inside circle) in Southern Brazil.