When the rains come in July, the thickly packed, deep pink, red and sometimes white flower spikes of the knotweed spring up all over the temperate Himalayas. The knotweed grows at heights of about 2000-4500 m. It is a slender, erect plant with ovate, heart-shaped, stem-clasping (stalkless) upper leaves. The leaves have pointed edges and are dark green. The solitary flower spikes are 5-15 cm long and densely packed with little flowers 3-6 mm long. The lower leaves are long-stalked. The rootstock of the knotweed is used in the tanning process and the plant is used as fodder.