a perennial herb of 30-60cm, grows in forests in hilly districts.
Leaves attach themselves oppositely on stem tops in 2-3 pairs,
somewhat apart from each other. Leaves are glossless green, with
spiny serrations on the margins. Spikes generally comprise two,
varying from 1 to occasionally 3-5; filaments, short, curve toward
inside to envelop pistils. Central stamens attach two anthers inside
their bases, and two stamens outside set the anthers one each. Bloom