Flowering Mar-Apr, Sep., Flowers about 2.8 cm across the lower lip, 4.4 cm long, in spikes of about 15 cm long. Leaves -9 cm long and -4 cm wide. Leaf margins with up- and downward pointing teeth that end with hard, sharp prickles. Mangrove swamps, along banks of estuaries and lagoons, in brackish wet places near the seashore. (JdV)
Along the coasts of Southeast Asia and North Australia.