A new species of Habranthus (Amaryllidaceae) from Argentina

 

G. Roitman¹, A. Castillo² and M. R. Barrios¹

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

 

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Summary: A new species of Habranthus is described and illustrated. H. correntinus is found in wet grasslands of northeastern Argentina. The new species resembles Habranthus tubispathus in size, but can be easily distinguished by the presence of bulblets, narrow dark green leaves, narrow pinkish tepals with darker bases, the longer style with larger style arms, and the presence of leaves at anthesis. A key to identify the species of the genus from Corrientes is provided.

Key words: Amaryllidaceae; Habranthus; Argentina.

Resumen: Una nueva especie de Habranthus (Amaryllidaceae) de Argentina. Se describe e ilustra H. correntinus, especie que crece en pastizales húmedos en el noreste de Argentina. Esta nueva especie se parece en tamaño a Habranthus tubispathus pero puede distinguirse facilmente por la precencia de bulbillos, hojas más angostas de color verde oscuro, los tépalos rosados con la base oscura, el estilo mas largo al gual que las ramas estigmáticas y la presencia de hojas durante la antesis. Se brinda una clave para identificar las especies del género provenientes de la provincia de Corrientes.

Palabras clave: Amaryllidaceae; Habranthus; Argentina.

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Habranthus Herb. is an american genus of Amaryllidaceae with about 35-45 species (Arroyo- Leuenberger, 1996; Howard, 2001; Bryan, 2002) the majority from Argentina, Southern Brazil, Bolivia, Paraguay, and Uruguay, 5 species in Mexico and 1 in the USA (Habranthus tubispathus (L´ Her.) Traub, possibly introduced from South America (Flagg et al., 2002). Habranthus belongs to the Tribe Zephyrantheae, with Zephyranthes and Haylockia as sister genera (Meerow et al., 2000). Habranthus can be distinguish from Zephyranthes Herb. by the presence of cernous flowers vs. erect flowers and stamens of 4 different lengths vs. stamens of 1 or 2 lengths.
During the last 6 years we have been collecting and cultivating species of Habranthus, Zephyrantes, Haylockia Herb., C.Presl., Hippeastrum Herb. and Hieronymiella Pax. from Argentina, travelling to the places where the species have been previously collected, included in some cases place where this plants have been collected only once (Roitman et al., 2006). In a trip to the Province of Corrientes, Argentina, we found a new species of Habranthus, distinctive by the presence of bulblets, and leaves being present at anthesis. 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). We made observations about the growth and phenology, during the last 4 years.

Habranthus correntinus Roitman, J. A. Castillo et M. R. Barrios sp. nov.

Planta bulbosa, bulbo bulbifero, foliis basalibus angustissimis linearibus, canaliculata, sub anthesi praesentibus, 12-15 cm longis x 0.5-1.5 mm latis, scape 11-13 cm alto, umbella uniflora, spatha 2,8 cm longa, 1/2 - 2/3 supra basim tubulosa, flore roseo, anguste infundibulari, ad 37- 40 mm longo, tubo tepalorum 2- 3 mm longo, segmentatis tepalorum 3.3.-3.5 cm longis 7-9 mm latis, stylo declinato 25mm longo. Fructus ignotus.
TYPE: ARGENTINA. Corrientes: Dpto. Capital. San Luis del Palmar. 27 Nov. 2002, M. R. Barrios s.n. (HOLOTYPE: BAA 25856). Figure 1.

Fig. 1. Habranthus correntinus A. Habit. B. Flower, frontal view. (From M.R. Barrios s.n., BAA 25856, holotype.)

Plant 15-20 cm, clumping. Bulb ovoid, 20-25 mm x 17-22 mm, prolonged 17-22 mm, prolonged into a very short neck; tunics brown; bulblets present. Leaves present at anthesis, dark green, canaliculate, linear, 12-15 cm x 0.5-1.5 mm. Scape 11-13 cm x 3 mm, 1-flowered. Spathe membranous, basally tubular for 20 mm, then bifid apically for 8 mm. Pedicel to 40-60 mm long. Flower light pink, 37-40 mm long, with darker distal edges and dark red abaxially at the base. Tepals oblanceolate, joined at the base for 2-3 mm; the outer tepals 35 mm x 9 mm, the inner ones 28 mm x 8 mm. Filaments fascicled-declined, rather incurved above; upper episepal 6 mm long, lateral episepal 10 mm long, lateral epipetal 12 mm long, lower epipetal 15 mm long. Anthers markedly falcate after the release of pollen, 4 mm long. Style declined, ca. 25 mm long. Stigma trifid, its divisions obliquely spreading at first, then recurved, ca. 2 mm long. Ovary elliptic-oblong, ca. 3 mm x 3 mm. Fruit and seed unknown. Capsule not seen.
A notable species resembles in size to Habranthus tubispathus but quite distinct in its pink flowers with darker margins and base (vs. bright yellow or orange or with fine dark red venation on a light pink background) , the long style (25 mm vs. 14 mm), the presence of bulblets (vs. absence of bulblets), the canaliculate narrow leaves 0.5-1.5 mm lat. (vs. flat broad leaves 5-9 mm lat) the presence of leaves during anthesis (vs. absence of leaves during anthesis) and the dark green leaves (vs. glaucous leaves). The specific epithet is taken from the Argentinean Province of Corrientes.
Distribution and habitat: Known only from northeastern Argentina, Province of Corrientes. Inhabits wet grasslands, with clay soils, in large populations. Elevation: 50-100 m.
Phenology: It flowers during November and December.

Key to the species of Habranthus from Corrientes province

A. 2-5 flowered spathe, leaves terete.

                                                            H. pedunculosus Herb.

A'. 1 flowered spathe, leaves flat or canaliculate not terete.

   B. Bulblets present.

      C. Flowers 9 cm long, 6 cm wide, leaves 30-50 cm long, 10-15 mm wide, flat, absent during anthesis.

                                                            H. brachyandrus (Baker) Sealy

      C'. Flowers 3.7-4 cm long, 3 cm wide, leaves 12-15 cm, 0.5-1.5 mm wide, caniculate, present during anthesis.

   B'. Bulblets absent.

                                                            H. correntinus H. tubispathus (L'Hér.) Traub

Acknowledgements

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

Bibliography

1. ARROYO-LEUENBERGER, S. C. 1996. Amaryllidaceae Juss. In: F. O. Zuloaga & O. Morrone (Eds.), Catálogo de las plantas vasculares de la República Argentina I. pp. 90-100. Monogr. Syst. Bot. Missouri Bot. Gard. 60: 1-332.         [ Links ]

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3. FLAGG, R. O., G. L. SMITH & W. S. FLORY. 2002. Habranthus. In: Flora of North America and North of Mexico, vol. 26, pp. 281-282. Oxford University Press, New York.         [ Links ]

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6. ROITMAN, G. I. MAZA & A. CASTILLO. 2006. Presence of Habranthus cardenasianus (Amaryllidaceae) in Argentina. Bol. Soc. Argent. Bot. 41: 95-98.         [ Links ]

Recibido el 20 de Junio de 2007
Aceptado el 19 de Marzo de 2008.