Vitex rehmannii has bark showing various shades of grey and brown at different stages or in different conditions. It becomes fissured into squares with age.
The leaves are five-foliolate, occasionally trifoliolate, growing in opposite pairs. The leaflets are oblong to elliptic, leathery and yellowish green to olive-green.
The flowers are cup-shaped with five lobes. The flower cup is white, the lobes mauve or purple. Many flower clusters can usually be seen on the trees from late spring through summer.
The pear-shaped dry fruit is black, almost enclosed by the persistent papery calyx (Coates Palgrave, 2002; Schmidt, et al, 2002).