The dehiscent legumes of Chloroleucon chacoense (Leguminosae, Mimosoideae) are highly predated. The seeds of an intermediate type (neither orthodox, nor recalcitrant) remain in latency until the rainy station start can germinate efficiently when are imbibed 36 h in water before the sown, reaching similar % than those treated with sand paper or sulphuric acid. The seeds lose their germinability when are treated with warm water, perhaps because it kills the embryo. The seedlings are developed in a high percentage (92%) although they do not receive scarification treatments. The scarified seeds increase their weight more than the no scarified, as the Baskin Index denotes. The ANOVA and MTG show that the mechanical and chemical treatments allow the seeds to germinate till 24 h since the sown. The “t” test highlights that the no scarified seeds exhibit high difference of weight only at 24 h since the sown; perhaps the seeds need that lapse of time to imbibe to start the germination. Between the unhealthy seeds, those with arrested development constitute a high percentage, and perhaps some problems in the reproductive system exist. The germination is epigeal, phanerocotyledonar, with photosynthesizing cotyledons, and the seedlings have two sub-opposite protophylls (one pinnate, the other bipinnate) and two or more alternate, bipinnate eophylls. This fact implies that the classification commonly used does not cover the variability existent in the Leguminosae. Studies are needed to elucidate the origin of the low density of individuals because the species is included in the RED BOOK.