SciELO - Scientific Electronic Library Online

 
vol.48 número1La familia Apocynaceae s. str. (Apocynoideae, Rauvolfioideae) en UruguayNovedades nomenclaturales en los géneros Lippia y Lantana (Verbenaceae) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Articulo

Indicadores

  • No hay articulos citadosCitado por SciELO

Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google

Bookmark


Darwiniana, nueva serie

versión impresa ISSN 1850-1702

Darwiniana vol.48 no.1 San Isidro ene./jun. 2010

 

SISTEMÁTICA Y TAXONOMÍA DE PLANTAS VASCULARES

Herbertia Zebrina (Iridaceae, Tigridieae, Cipurinae) a new species from Rio Grande do Sul State (Brazil)

Leonardo Paz Deble1

1Curso de Ciências Biológicas, URCAMP, 96400-110, Bagé, RS, Brazil; deble.biol@gmail.com

Abstract

Herbertia zebrina, a new species from Serra do Sudeste, Rio Grande do Sul State (Brazil) is described and illustrated, and its taxonomic affinities are discussed. Comments about geographic distribution, conservation and a key to the Brazilian species of Herbertia are also provided.

Keywords. Brazil; Herbertia; Iridaceae; Taxonomy.

Resumen

Herbertia zebrina (Iridaceae, Tigridieae, Cipurinae) una nueva especie del estado de Rio Grande do Sul (Brasil)

Se describe e ilustra Herbertia zebrina, una nueva especie para Serra do Sudeste, Rio Grande do Sul (Brasil), y se discuten sus relaciones taxonómicas. Se incluyen comentarios sobre su distribución geográfica y conservación, y se provee una clave para identificar las especies brasileñas de Herbertia.

Palabras clave. Brasil; Herbertia; Iridaceae; Taxonomía.

INTRODUCTION

The genus Herbertia Sweet (Iridaceae, Tigridieae, Cipurinae ) comprises six species: H. crosae Roitman & A. Castillo, H. darwinii Roitman & A. Castillo, H. lahue (Molina) Goldblatt [= H. furcata (Klatt) Ravenna], H. pulchella Sweet [= H. amatorum C. H. Wright], H. quareimana Ravenna and H. tigridioides (Hicken) Goldblatt, that occur on grasslands and stony grasslands from Rio Grande do Sul (Brazil), Uruguay, Argentina and Chile, in South America and Herbertia lahue subsp. caerulea (Herb.) Goldblatt, found in the southern U.S.A. (Roitman & Castillo, 2004; Roitman & Castillo, 2007; Roitman & Castillo, 2008: Roitman et al, 2008).
During the preparation of the catalogue of the family Iridaceae for Rio Grande do Sul State, Brazil, my attention was drawn to an unusual specimen of Herbertia. Examination of herbarium material (including types) and field research, led me to recognize a new species, Herbertia zebrina Deble that was found growing on stony grasslands between Encruzilhada do Sul and Amaral Ferrador municipalities. With the addition of this new species, the genus is comprised of seven species, six of them occurring in Brazil.

Results.

Herbertia zebrina Deble, sp. nov. TYPE: Brazil, Rio Grande do Sul, Amaral Ferrador, próximo a divisa com Encruzilhada do Sul, propriedade da Pinheira, em cerro pedregoso, na subida para o topo, 30°39'55.37"S, 52°23'59.52"W, 21-XII- 2008 (fl. and fr. ), L. P. Deble, A. S. de Oliveira-Deble & M. Scipioni 10.844 (holotype SI). Figs. 1 and 2.


Fig. 1. Herbertia zebrina. A, plant. B, spathe with flower. C, lateral view of flower. D, spathe with capsules. E, basal part of plant. F, basal part of leaf. G, apical part of a leaf. H, stem bract. I, inner tepals. J, flower with tepals removed showing androgynoecium. K, capsule. L, seeds. M, upper part of style arm showing stigma and anthers apex. From Deble et al. 10.844 (SI).


Fig. 2. Herbertia zebrina. A, flower and general habit. B, detail of lateral view of flower.

Ab Herbertiae crosae, tepalis externis albidis (non lilacinis), tepalis internis albidis et atropurpureis striatis (non lilacinis et luteis maculatis), truncatis vel rotundatis (non acutis), antheris minoribus (2.3-2.7 mm non 4-5 mm), optime distincta.

Plant up to 15-20 cm high above ground, stems subterranean in proximal third. Bulb subglobose, 13-17 mm wide, sometimes prolonged in a short collar. Leaves 2-3, plicate, narrowly linear, 7-12 cm long, and 0.2-0.3 cm wide. Spathes 2; inflorescence 2-flowered rhipidium; spathes green, the lower 1.2-1.6 cm long, the upper 1.8-2.6 cm long, both with membranous edges; pedicel filiform, up to 1 cm long. Flower white, radially symmetrical, 3.5-4.5 cm wide. Tepals series distinctly dissimilar. Outer tepals obovate, 15-19 mm long, 9-11 mm wide, with 9-14 dark purple parallel stripes and a yellow medial stripe at the base. Inner tepals white and dark purple striped, unguiculate, 6-7 mm long; claws 2-2.5 mm long, 1.1-1.4 mm wide; blades 4-5 mm long and wide, apex rounded to truncate, slightly reflexed. Filaments united in a column, 6.5-9 mm long, free apically for 1.5-2.5 mm, dark purple-spotted along the column and dark purple in the proximal third; anthers linear, curved at dehiscence, 2.3-2.7 mm long; pollen yellowish. Ovary 3.5-5 mm long, 2-3 mm wide. Style 5-6.5 mm long. Style arms channeled, 3.5-4.5 mm long, at apex bifid for 0.5-1 mm, the divisions divaricate, recurved, apically stigmatose. Capsule broadly oblong, 6-8 mm long, 4-4.5 mm wide. Seeds oblong to obconical, angulated, reddish-brown, epidermis striate, 0.9-1.3 mm long.

Etimology. The specific epithet refers to the unusual striped standard of inner tepals.

Distribution and habitat. Herbertia zebrina was found growing on stony grasslands southeast of Encruzilhada do Sul and northwest of Amaral Ferrador cities; however the geographic distribution probably includes also southwest of Dom Feliciano municipality. Material with flowers and fruits are collected during December-January. Herbertia zebrina is sympatric with several Iridaceae species: Herbertia lahue subsp. amoena (Griseb.) Goldblatt, H. pulchella, Cypella herbertii Herb. subsp. herbertii, Cypella brasiliensis (Baker) Roitman et J.A. Castillo, Gelasine elongata (Graham) Ravenna, Sisyrinchium micranthum Cav. and S. palmifolium L.

Observations. Herbertia zebrina is easyly distinguished from the remaining co-generic species by the rounded to truncate, white and dark purple striped inner tepals, and by the presence of white outer tepals. White flowers has been seldom reported for Herbertia lahue and H. pulchella, as atipic individuals growing among regular ones (G. Roitman, com. pers.). The androgynoecia display free filaments at the apex for 1.5-2.5 mm; three other species show this characteristic: Herbertia crosae, H. quareimana and H. pulchella, and probably the first-one is most closely related to H. zebrina; both display narrowly linear leaves, a yellow medial stripe at the base on outer tepals, filaments purple-spotted along the column, similar capsules and seeds; however H. crosae shows pale lilac flowers (vs. white), acute inner tepals (vs. rounded to truncate), with blades lilac (vs. white and dark purple striped) and bigger anthers (4-5 mm vs. 2.3-2.7 mm long).
The rounded to truncate shape of inner tepals of Herbertia zebrina are very distinctive from the rest of the species of Herbertia which have narrow acute shape, and resemble the upper part of the inner tepals of Cypella hauthalii (Kuntze) R. C. Foster, C. brasiliensis and C. unguiculata (Baker) Roitman & A. J. Castillo; however, the androgynoecium of all cited species shows erect anthers, the presence of long style crests in the first species and capitate style arms in the two latter species, whereas Herbertia zebrina shows divergent anthers and bifid style arms. The androgynoecium features were decisive to include the new taxon within Herbertia, but its relationships with other species is not clearly defined. Although further molecular studies have to be performed, preliminary DNA sequence studies showed that there is a close relationship between Herbertia and Cypella (Reewes et al., 2001; Goldblatt & Manning, 2008).
The geographic distribution of Herbertia zebrina comprises only 400 km2 and the area of occurrence is smaller than 10 km2; the populations are fragmented and with few individuals. Due to the rarity, fragmentation of populations, and observed threats, it seems prudent to include H. zebrina in the Critically Endangered category of the IUCN Red List of endangered plant species according to the following criteria (IUCN, 2001): CR B2a,b (i,ii,iii,iv,v); C 2a(i).

Paratypes
BRAZIL. Rio Grande do Sul, Encruzilhada do Sul, Coxilha do Vento, 27-XII-2008 (fl.), L. P. Deble, A. S. de Oliveira-Deble & M. Scipioni 10.845 (SI); idem, 4-I-2009 (fl. and fr.), L. P. Deble & A. S. de Oliveira-Deble 10.846 (NAR).

Key to the Brazilian species of Herbertia

1. Inner tepals dark purple-striped, apex rounded totruncate, white. Flowers white. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. zebrina
1. Inner tepals not dark striped, apex obtuse to acute, lilac to dark violet rarely white. Flowers pale lilac, violet or blue rarely white . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2(1). Androgynoecium filaments free for 3-5 mm long at the apex. Flowers blue or blue-violet. Outer tepals with a white to light blue streak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H. pulchella
2. Androgynoecium filaments entirely united, forming a column or free up to 1.5 mm long at the apex. Flowers pale violet, blue-violet or violet, without a white to light blue streak . . . . . . . . . . . . . . . . . . . . . 3
3(2). Flowers pale lilac. Outer and Inner tepals lilac and yellow maculate at the base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. crosae
3. Flowers blue-violet or violet. Outer tepals whitish and dark violet spotted at the base. Inner tepals dark violet without a yellow macula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4(3). Flowers 55-65 mm wide. Outer tepals without a yellow medial stripe at the base. Androgynoecium filaments free for 1-1.5 mm long at the apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H. quareimana
4. Flowers 30-55 mm wide. Outer tepals with a yellow medial stripe at the base (rarely absent). Androgynoecium filaments entirely united, forming a column; anthers attached directly to the filament column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5(4). Leaves 10-20 mm wide. Style arms channeled, secondary divisions recurved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. darwinii
5. Leaves 4-10 mm wide. Style arms not channeled, secondary divisions straight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. lahue

Acknowledgements

I thank Erika Werner (SI) for sending the bibliography and Rafael Matielo for assistance in the elaboration of the figure 2. My gratitude also goes to Anabela Deble and Marcelo Scipioni for photographs of the holotype and companionship during the trip from Serra do Sudeste. Finally, thanks to Germán Roitman for a valuable review and helpful comments on the manuscript.

Bibliography

1. Goldblatt, P. & J. C Manning. 2008. The Iris Family. Natural History and Classification. Portland: Timber Press.         [ Links ]

2. Reeves, G.; M. W. Chase, P. Goldblatt, P. J. Rudall, M. F. Fay, A. V. Cox, B. Lejeuna & T. Souza-Chies. 2001. A phylogenetic analysis of Iridaceae based on four plastid sequence regions: trnL intron, trnL-F spacer, rps4 and rbcL. American Journal of Botany 88: 2074-2087.         [ Links ]

3. Roitman, G. & J. A. Castillo. 2004. A new species, Herbetia crosae (Iridaceae), from Uruguay. Brittonia 56: 361-364.         [ Links ]

4. Roitman, G. & J. A. Castillo. 2007. Novedades taxonómicas y nomenclaturales para la flora vascular del cono sur de Sudamérica: nuevas combinaciones en Iridaceae. Darwiniana 45: 236-241.         [ Links ]

5. Roitman, G. & J. A. Castillo. 2008. Herbertia darwinii (Iridaceae: Tigridieae: Cipurinae), a new species from South America. Boletín de la Sociedad Argentina de Botánica 43: 311-314.         [ Links ]

6. Roitman, G; I. Maza & J. A. Castillo. 2008. Iridaceae, in F. O. Zuloaga, O. Morrone & M. J. Belgrano (eds.), Catálogo de Plantas Vasculares del Cono Sur, vol. I. Monographs in Botany from the Missouri Botanical Garden 107: 423-453.         [ Links ]