The silica-phellem block and stomate tubercle on 3rd leaf are underdeveloped, the tubercle of stomate block is small and dense in japonica, big and sparse in O.
Stems caespitose, simple or many branched, 60-150 cm tall, ca. 1 cm in diam., antrorsely setulose, armed with spreading stinging hairs, dense in lower parts, sparser in upper parts.
The prolabium of complete BCL operated on with straight line suture method had muscle fibers proliferated from the lateral lips, but the fibers were sparse and also had ultra structure variations.