pallidum is the barley most frequently cultivated in northern Europe and northern Asia.
Trewianum, and L. pallidum, from Colorado.
Syphilis is caused by the spiral- or coil-shaped bacteria (spirochete), Treponema pallidum.
Treponema pallidum subspecies endemicum, the bacteria that causes bejel, is very closely related to the one that causes the sexually transmitted form of syphilis, but the method of transmission is different.
T. pallidum subspecies endemicum is passed on mostly among children living in poverty in unsanitary environments and with poor hygiene.