<p>Quelites are plants whose leaves, tender stems, and, occasionally, immature inflorescences are consumed as cooked vegetables. The objective of this study was to analyze the nutritional properties and the effect of heat treatment on <i>I. dumosa</i> leaves collected in the spring and fall of two consecutive years to evaluate the stability of their nutraceutical potential. Significant amounts of crude fiber (14.73%), protein (4.26%), Fe, P, Mn, and Cu (52.26, 922.04, 5.41, and 2.18&#xa0;mg·100&#xa0;g^− 1, respectively) were discovered, which is greater in value than those of similar quelites, such as purslane and quintoniles. The nutraceutical potential of <i>I. dumosa</i> was not affected by the heat treatment. However, it was affected by the harvest season, as differences in phenolic content and antioxidant capacity were observed between harvest years. Consequently, the integration of <i>I. dumosa</i> into the human diet is advocated, given that, in addition to its nutritional contribution, heat treatment does not alter its antioxidant capacity. This study constitutes the first report on <i>I. dumosa</i> and aims to highlight its nutritional properties and promote its conservation and consumption.</p>