Tendril unbranched or bifurcate. Inflorescence usually a polychasium. Seeds elliptic, obovoid-elliptic, or obtriangular, surface smooth, corrugated, or with strumose protuberance or ribs.
Evolution is regarded as a branching process, whereby populations are altered over time and may speciate into separate branches, hybridize together, or terminate by extinction.
A mutant, TS-N-121 was obtained by mutation and plate screening from a parent strain Mycobacterium fortuitum MF2 , which could transform sterol into androstanedione as the main product.
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.