In this work, a morphological characterization of germplasm accessions of wild Brazilian species of peanut, section Arachis was accomplished. Also, an analysis of the genetic similarity among accessions and between species was evaluated. The experiment was undertaken from 1993 to 1996, at the Campinas Experimental Station of the Instituto Agronômico (IAC). Accessions evaluated were made available by the Wild Arachis Genebank of Embrapa Recursos Genéticos e Biotecnologia (CENARGEN - Brasília, DF) and include A. palustris Krapov., W.C. Gregory & Valls, A. decora Krapov., W.C. Gregory & Valls, A. praecox Krapov., W.C. Gregory & Valls and A. stenosperma Krapov. & W.C. Gregory. Quantitative and qualitative phenotypic data were collected according a list of morphological descriptors. Results showed that accessions of A. stenosperma are very similar, despite the large geographical distance between them. Also, this species forms an isolated group, distant from the other species. Characters such as main stem diameter, fruit and seeds length were useful to separate A. stenosperma from the other species. Arachis decora has a high variation between accessions for many characters used. Arachis palustris shows high morphological variation between accessions, although only two accessions were studied, concerning plant height, seed width, peg, isthmus, leaflet, rachis, and main stem dimensions, presence or absence of hairs on the leaflet. Arachis praecox, represented in this work by a single accession, is more similar to A. decora than to other species.
wild peanut; morphological characterization; Arachis
