Calydorea minima (Iridaceae, Tigridieae) a new species from South America

Germán Roitman¹ y Alberto Castillo²

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

Summary: Calydorea minima (Iridaceae, Tigridieae) is described from stony grasslands of northern, Argentina and Paraguay. The new species resembles Calydorea azurea , but it can be easily distinguished by its smaller habit (10- 15 cm vs. 25- 35 cm ), its smaller flowers with acute tepals (1.5- 2.2 cm diameter vs. 4.4- 5.3 cm diameter), and by its linear extremely narrow leaves (0.5- 0.7 mm vs 3 a 6 mm wide). A key, to identify the species of the genus from Argentina, Paraguay and Uruguay is provided.

Key words: Iridaceae; Tigridieae; Calydorea; South America.

Resumen: Calydorea minima (Iridaceae, Tigridieae) una nueva especie de Sud America. Se describe Calydorea minima (Iridaceae: Tigridieae) proveniente de afloramientos de roca del norte de, Argentina y Paraguay. Esta nueva especie se asemeja a Calydorea azurea , pero puede distinguirse fácilmente por su menor tamaño (10- 15 cm vs. 25- 35 cm ), sus flores más pequeñas (1.5- 2.2 cm vs. 4.4- 5.3 cm de diámetro), con tépalos agudos y sus hojas lineares muy angostas (0.5- 0.7 mm vs 3 a 6 mm de ancho). Se incluye una clave para identificar las especies del género que habitan Argentina, Paraguay y Uruguay.

Palabras clave: Iridaceae; Tigridieae; Calydorea; Sud America.

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 the range of the genus to northern South America, Mexico, and southern North America (Florida). Tamia Ravenna has been also merged in Calydorea (Di Tullio et al ., in press), which now includes 25 species, 7 of which were reported in Argentina, Paraguay and Uruguay.
During a trip to the north of Corrientes, in spring of 2002, we found populations of a very tiny species of Calydorea . Bulbs collected in the field, were cultivated in the J. O. Hall Garden facilities (Facultad de Agronomía, Universidad de Buenos Aires, 34º35' S, 58º 30' W) and for the last 4 years observations on growth and phenology, were carried out. During spring of 2006 we collected and made vouchers of this plant in the same place. Furtheremore in a visit to CTES herbatium we found a voucher of this species from Paraguay. Detailed observations of the habit, size and flowers led us to treat this as a new species, allied to C. azurea Klatt, a species restricted to grasslands in Entre Ríos and south of Corrientes provinces in Argentina.
Calydorea minima Roitman & A. Castillo, sp. nov (Fig. 1 A-C).

Fig. 1. Calydorea minima Roitman et A. Castillo. A. Plant; B. Flower fron view; C. Detail of the free stamens and the style. From the holotype, Roitman, s.n. (BAA 25701).

Ab Calydorea azurea , herbae 10- 15 cm alta, foliis angustissimis, floribus parvioribus, tepaliis angustioribus recedit.
Type: ARGENTINA, Corrientes. Dpto. : Santo Tomé. Cercanías de Garruchos, 10-X- 2006, G . Roitman s.n. (BAA 25701). Paraguay, Dpto .: Caaguazú, Coronel Oviedo. Ruta 2. Km 140. Krapovickas y C. L. Cristobal 13429 (CTES). Herb, 10- 15 cm high. Bulb subglobose, 8- 12 mm wide, covered by dark-brown, membranous coats, prolonged upwards into a neck. Leaves 1-2, 6- 8 cm long, 0.5- 0.8 mm wide plicate, linear, green at anthesis, erect, 6- 8 cm long, 0.5- 0.8 mm wide. Inflorescence a 1-2 -flowered rhipidium; spathes green, the outer 2- 2.5 cm long, the inner 1- 1.8 cm long. Flower 1.5- 2.2 cm diameter, lilac with violet dots and a yellow stripe at the base, radially symmetrical, 1.5- 2.2 cm diameter. Outer tepals 0.7 - 1.1 x 0.3- 0.5 cm , oblanceolate, with acute apex, 0.7 - 1.1 x 0.3- 0.5 cm ; inner tepals 0.6-1.0 x 0.3- 0.6 cm , elliptic, with acute apex, 0.6-1.0 x 0.3- 0.6 cm . Filaments 1- 1.5 mm long free, yellow 1- 1.5 mm long; anthers 2.5- 3 mm long linear, curved at dehiscence, 2.5- 3 mm long. Pollen yellow. Ovary 3-4 x 1- 2.5 mm . Style 2 mm long ,yellow 2 mm long, with truncated branches, 2.5- 3.2 mm long. Capsule 0.7- 1 cm x 0.4- 0.6 mm globose 0.7- 1 cm x 0.4- 0.6 mm , seeds angled, 1mm long light brown, 1mm long.
This new species resembles Calydorea azurea which has flowers of the same color, but it can be easily distinguished from C. azurea by its smaller habit (10- 15 cm vs. 25- 35 cm ), its linear, extremely narrow leaves (0.5- 0.7 mm vs 3 a 6 mm wide), its smaller flowers (1.5- 2.2 cm diameter vs. 4.4- 5.3 cm diameter), and by its acute apex of the tepals (vs. rounded apex tepals).
Distribution and Ecology. It is found near Garruchos (Argentina, Corrientes), in stony grasslands, growing with Cypella hauthalii (Kuntze) R.C.Foster subsp. opalina Ravenna and Cypella laeta Ravenna, and in the South of Paraguay.
Etymology: It is the smallest species in the genus.

ACKNOWLEDGEMENTS

We are grateful to R. D. Tortosa for his constructive criticism on an earlier draft and N. Valgañon for the illustration of the species.

BIBLIOGRAPHY

DI TULLIO, G. ROITMAN & G. BERNARDELLO. Tamia (Iridaceae), a synonym of Calydorea : Cytological and Morphological Evidences. Syst. Bot. (in press).         [ Links ]

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

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

ROITMAN, G & A. CASTILLO. 2005 . Calydorea alba (Iridaceae: Tigridieae), a new species from Uruguay. Bol. Soc. Argent. Bot . 40: 311-312.         [ Links ]

Recibido el 17 de Abril de 2007,
aceptado el 13 de Agosto de 2007.