Dalbergia armata is a deciduous, woody, robust climber. It tends to grow into a shrub, sometimes even developing into a tree, up to 5 m tall and as a climber can reach 15 m. Although deciduous, new growth appears rapidly, with the leaflets closing in overcast weather. The trunk reaches 150 mm in diameter in full growth and is armed with strong, woody spines, up to 100 mm long, that stand stiffly off the main stem and branches. The bark is dark brown to grey, almost a charcoal colour.

The leaves are finely compound and are dark green on their upper surfaces and paler green below, with fine velvety hairs when young, that are lost later. The alternate leaves are up to 80 mm long. The leaflets are oblong to elliptic and come in pairs of ten to twenty, including a terminal leaflet. The flowers are small, pea-shaped, sweetly scented and are creamy white. They are produced in axillary or terminal heads or clusters up to 100 mm long, in early summer (from October to November).

The fruits, which come in the form of lemony yellow to pale brown, flat papery pods measuring 50 × 20 mm, are often produced in abundance. The indehiscent fruits, which hold 1 to 3 seeds each, appear in clusters on horizontal branch tips, in late summer (from January to May ).