fibras libriformes septadas. A estrutura corresponde ao descrito para outras espécies do mesmo gênero, bem como para as antigas "acácias" do subgênero Aculeiferum. Palavras-chave: Acacia adhaerens, Fabaceae, Leguminosae, Mimosa martiusiana, Mimosoideae, Senegalia martiusiana, Anatomia da madeira.The wood of Senegalia martiusiana (Fabaceae: Mimosoideae) is anatomically described and illustrated with photomicrographs. In its structure it should be noted the following features: semi-diffuse porous wood; vessels mostly solitary; short vascular elements; simple perforation plates; short and vestured inter-vessel pits; scarce axial parenchyma, with 2-5 cells per axial series; homogeneous rays, with 1-2 cells wide; and libriform septate fibers. The anatomical structure fits the description to other species of the same genus, as well as to other "acácias" from subgenus Aculeiferum.