A Second Species of Seegeriella (Orchidaceae: Oncidiinae)

摘要

Seegeriella crothersii, a new species from Ecuador, is described and illustrated. The new species is compared with S. pinifolia, from which it mainly differs by the laterally flattened leaves, the paniculate inflorescence with short, 2-flowered secondary branches, the much smaller lip, provided with shorter lateral lobes, and the greenish yellow sepals and petals. A key to the species of Seegeriella is provided. The subtribe Oncidiinae is one of the largest orchid groups in the Neotropics (with an estimate of 1700 species in 55 genera), where it occupies a vast array of epiphytic habitats, varying from the larger, shaded axes of the inner canopy to the driest and ephemeral sites of the terminal twigs. Species of the Oncidiinae also greatly differ insize, varying from tall plants like specimens of Lophiaris Raf. (syn. Tricho-centrum Poepp. & Endl.) and Cyrtochilum Kunth, with single vegetations that can exceed 70 cm in length, to the diminutive habit of species of Erycina Lindl., Macroclinium Barb.Rodr. and Hopneisterella Rchb.f., barely reaching 1 cm in size. Reduction in plant size is often correlated, in the Oncidiinae, to modifications in vegetative architecture and retention of juvenile traits leading to paedomorphism, as well as in life history strategies (Chase 1988) and reduction in chromosome numbers (Chase et al. 2005).