Notes on Cipura (Iridaceae) in South and Central America, and a New Species from Venezuela

Abstract

Cipura is a small genus of Iridaceae-Tigridieae that is widespread in tropical South and Central America, Mexico, and the West Indies. It comprises at least five species and is at present poorly understood. The type species, C. paludosa Aublet, is often treated as including the similar C. campanulata Ravenna (syn. C. inornata Ravenna), and the differences between the two are detailed. A new species, C. rupicola, is described from Territorio Federal Amazonas, Venezuela. It is closely allied to the only other known yellow-flowered species, C. xanthomelas Martius ex Klatt (syn. C. flava Ravenna), of interior Brazil. The basic chromosome number in Cipura is x = 7 and chromosome numbers have been established here for C. xanthomelas and C. rupicola, both tetraploid, 2n = 4x = 28. During preparation of treatments of Iridaceae for three regional floras, Flora Mesoamericana, Flora de Nicaragua, and Flora of the Venezuelan Guayana, the genus Cipura Aublet posed several problems in typification and delimitation of species. As a result we studied this small genus in some detail. Our conclusions relate to the genus as a whole and are presented in the form of a review. A new species, C. rupicola, is described from western Venezuela, and two more undescribed species are included in a key to the genus but are not published as new species here for reasons given below. A complete revision of Cipura is being prepared by P. Ravenna as part of a treatment of Iridaceae for Flora Neotropica. Cipura is one of a distinctive group of New World Iridaceae comprising tribe Tigridieae (Goldblatt, 1982), which is characterized by a bulbous rootstock, plicate leaves, and a basic chromosome number of x = 7. The first genus in the alliance to be described (Aublet, 1775), it was based on C. paludosa, from what is now French Guiana. Cipura comprises five or probably a few more species, distributed from southern Mexico in the north to Bolivia, southern Brazil, and Paraguay in the south (Fig. 1). Cipura paludosa occurs over almost the entire range of the genus, but the other species have narrower and sometimes very restricted ranges. Cipura is closely related to the larger genus Cypella Herbert from which it differs in having erect inner tepals that partly conceal the stamens and style-stigma apparatus and a large cauline leaf inserted at the flowering stem apex just below the single or few and closely set rhipidia (spatheenclosed inflorescence units). As in Cypella and several other genera of Tigridieae, the fugacious flowers have broadly clawed outer tepals; inner tepals with an adaxial nectariferous area on the limb (usually concealed by a fold in the tepal surface); free stamens with weak filaments; and anthers adhering to the style branches. The style divides above into three thickened