The deficiency of specialized bibliography cause great difficulties and changes in the
identification of the species, in the procedures of a Seed Testing Laboratory. Therefore, through the
characteristics of seeds and fruits of some Convolvulaceae species, which occur in Brazil and in other
countries, were elaborated a taxonomical key, morphological descriptions and drawings in order to help the
identification of Convolvulus crenatifolius Ruiz et Pav., Dichondra microcalyx
(Hall.f.) Fabris., Ipomoea amnicola Morong, I. martii Meissn., I. pandurata (L.) G.F.W.Meyer, Jacquemontia
tamnifolia (L.) Griseb., Merremia dissecta (Jacq.) Hall.f. and M. macrocalyx (Ruiz et Pav.) O?Donell. The morphological descriptions
of the seeds were based mainly on the colour and pilosity of the seed coat (surface) and hilum area, size and
outline of the hilum, which are very stable characteristics. The shape of the seeds of the Convolvulaceae,
vary with the amount of seeds developed in the fruit and is not a consitent characteristic. Are included the
common names and the crops in which the species is considered as a weed.