A new species of Croton sect. Luntia (Euphorblaceae) from western Amazonian Brazil

A new species of Croton, C. subasperrimus, is described and illustrated from a previously unexplored area of Amazonas State, Brazil. It belongs to Croton sect. Luntia subseet. Cuneati because of its pinnate leaf venation, slightly reduplicate pistillate calyx, partially bisexual basal cymules, presence of lepidote trichomes, low stamen number, and multifid stigmas. It differs from related species in its stellate-lepidote trichomes that sometimes have tall porrect central rays and in its smaller, concolorous leaves with an obtuse base and stipitate glands along the margins.