Lactarius repraesentaneus namely repraesentins B and C. These compounds were shown to promote the radicle elongation of lettuce seedlings by 136%, 118% and 184% at 67 ppm, respectively. Other compounds reported in 2006 are repraesentins D, E, and F. Repraesentin E showed the strongest growth promotion activity, 164% at 3.6 µm, of the three compounds toward the radicle elongation of lettuce seedlings. Lactarius repraesentaneus Lactarius repraesentaneus, commonly known as the northern bearded milkcap, the northern milkcap, or the purple-staining milkcap, is a species of fungus in the Russulaceae family. It has a northerly distribution, and is found in temperate regions of North
Drill bit shank shaft and shank, is usually of the same diameter. It is held usually in a three-jaw drill chuck. Bits of diameter too small to grip firmly can have straight shanks of larger diameter than the drill, which can be held firmly in a standard size collet or chuck. Large drill bits can have straight shanks narrower than the drill diameter so that they can be fitted in chucks not able to chuck the full diameter. Such a drill bit is called a reduced-shank or blacksmith's drill. For example, this allows a bit to be used in a pistol-grip drill's chuck.