Calydorea alba (Iridaceae: Tigridieae), a new species from Uruguay

 

G. G. Roitman¹ and A. Castillo²

¹ Cátedra de Jardinería. Facultad de Agronomía, Universidad de Buenos Aires. Av. San Martín 4453. 1417 Buenos Aires. E-mail: roitman@mail.agro.uba.ar
² Jardín Botánico de Ezeiza. Jujuy 1037. 1804. Ezeiza, Buenos Aires. E-mail: ezeizabotgard@hotmail.com.

 

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Abstract: Calydorea alba is described from wet grasslands of northern Uruguay. The new species resembles Calydorea azurea, but can be easily distinguished by the smaller white flowers (3.2-3.6 cm wide vs. 4.4-5.3 cm wide), and linear subulate not truncate, style branches.

Key words: Iridaceae; Tigridieae; Calydorea; Uruguay.

Resumen: Calydorea alba (Iridaceae: Tigridieae), una nueva especie de Uruguay. Se describe Calydorea alba proveniente de pastizales húmedos del norte de Uruguay. Esta nueva especie se asemeja a Calydorea azurea, pero puede ser fácilmente distinguida por sus flores blancas más pequeñas (3,2-3,6 cm vs. 4.4-5.3 cm, de diámetro), y las ramas de estilo lineares, subuladas no truncadas.

Palabras clave: Iridaceae; Tigridieae; Calydorea; Uruguay.

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INTRODUCTION

Calydorea Herbert is a genus of Iridaceae, tribe Tigridieae, centered in temperate South America. It is defined by the subequal tepals spreading from the base, free stamens, short, slender style branches with simple, obtuse to emarginate apices. The genus was expanded by Goldblatt & Henrich (1991) to include Salpingostylis Small, Cardiostigma Baker, Itysa Ravenna, and Catila Ravenna, thus extending its range to northern South America, Mexico, and southern North America (Florida). Tamia was described by Ravenna. (2001) based on Calydorea pallens. That species is intermediate between Calydorea in the narow sense and Catila, a monotypic genus that was included in Calydorea by Goldblatt & Henrich (1991). Following this taxonomy, and with the addition of C. alba, Calydorea includes 24 species.

During field trips to Uruguay in spring of 2003, we found populations of a Calydorea species with white flowers, maked violet and yellow in the center, narrow more tapering tepals and subulate style branches. Detailed observations of the flowers led us to treat this as a new species, most closely allied to the blue-flowered C. azurea a species restricted to grasslands in Entre Ríos and Corrientes provinces in Argentina which has broadly oval tepals and truncate style branches.

Calydorea alba Roitman & A.Castillo sp. nov. (Fig. 1 a, b).

Fig. 1. Calydorea alba. a. Flower, b. Staminal column and stygma. From the holotype, Roitman, Tourn&Panziera s.n. (BAA 25500).

Ab Calydorea azurea, floribus parvioribus, albis, ramis styli linearibus subulatis differt.

Type: URUGUAY. Dpto. Artigas: Artigas, 9-X-2003 in wet grasslands, G. Roitman, G. M. Tourn & M. Panziera s.n. (BAA 25500).

Herb, 22-25 cm high. Bulb subglobose, 15-20 mm wide, covered by dark-brown, membranous coats, prolonged upwards into a neck. Leaves 2-4, plicate, linear, green at anthesis, erect, 10-12 cm long, 1-2 mm wide. Inflorescence a 1-2 -flowered rhipidium; spathes green, the outer one 3-3.5 cm long, the inner 1.5-2.5 cm long. Flower white with violet dots and a yellow stripe at the base, radially symmetrical, 3.2-3.6 cm diameter. Outer tepals lanceolate, tapering, 1.6-1.9 x 0.5-0.8 cm; inner tepals lanceolate, 1.4-1.7 x 0.4-0.7 cm. Filaments free, yellow 2 mm long; anthers linear, curved at dehiscence, 4-5 mm long. Pollen yellow. Ovary 4.5-5 x 1.5-2 mm. Style yellow 4 mm long, style branches 3, 4-5 mm long, subulate. Capsules and seeds unknown.

Obs.: This new species resembles Calydorea azurea Klatt which has the same heigth, but can be easily distinguished from it by the smaller white flowers (3.2-3.6 cm wide vs. 4.4-5.3 cm wide), and the subulate style branches (vs. style branches truncated).

Distribution and Ecology: Uruguay, Dpto. Artigas, and probably in S Brazil. It was found near Artigas, growing in wet grasslands with Cypella osteniana Beauverd subsp. aurantiaca Roitman & J. A.Castillo.

Etymology: It is the only species of the genus with white flowers.

ACKNOWLEDGEMENTS

We are grateful to R. D. Tortosa for his constructive criticism on an earlier draft; the anonymous reviewers of the manuscript, G. M. Tourn and M. Panziera for field assistance, and N. Valgañon for the illustration of the species.

BIBLIOGRAPHY

GOLDBLATT, P. and J. HENRICH. 1991. Calydorea Herbert (Iridaceae-Tigridieae): Notes on this New World genus and reduction to synonymy of Salpingostylis, Cardiostigma, Itysa, and Catila. Ann. Missouri Bot. Gard. 78: 504-511.         [ Links ]

RAVENNA, P. 2001. The Iridaceae of the Cuyo region Argentina. Onira 6: 1-18.         [ Links ]

Recibido el 31 de Agosto de 2005
Aceptado el 01 de Noviembre de 2005.