M. kavaiense is a shrub or small tree that reaches a height of 4–10 m (13–33 ft).
 The bark is dark grey and made up of rectangular or oblong platelets.
 The pinnate leaves are composed of 4 to 8 leaflets, each around 3 cm (1.2 in) in length.
 The bisexual flowers have pink to rose sepals and red anthers.
 They form on pink to red terminal racemes 4–7 in (10–18 cm) in length.
The flat, thin seed pods are 8 cm (3.1 in) long, 5 cm (2.0 in) wide, and contain 2 to 4 oval-shaped seeds.
Blooming takes place from December to March.
M. kavaiense is a shrub or small tree that reaches a height of 4–10 m (13–33 ft).  The bark is dark grey and made up of rectangular or oblong platelets.  The pinnate leaves are composed of 4 to 8 leaflets, each around 3 cm (1.2 in) in length.  The bisexual flowers have pink to rose sepals and red anthers.  They form on pink to red terminal racemes 4–7 in (10–18 cm) in length. The flat, thin seed pods are 8 cm (3.1 in) long, 5 cm (2.0 in) wide, and contain 2 to 4 oval-shaped seeds. Blooming takes place from December to March.
Mezoneuron kauaiense