Crack doesn’t grow on trees, but sometimes it can seem it grows on crack dealers.An otherwise mundane entry in the Seattle Police Department’s blotter today about a man arrested for failure to register as a sex offender had one notable aspect: the guy just kept producing crack.When bicycle officer in Belltown initially brought the 41-year-old into the precinct last night, they found 2.5 grams of the drug on him. Then, as he was being transported to his holding cell, another 1.4 grams of crack fell out of his pant leg. Once in the cell, police found another .1 grams of crack on the floor.From the sounds of it, he was a modern day Hansel, leaving a trail of cocaine so he could find his way back to Bell and 2nd. The unidentified man was booked in King County Jail for failing to register as a sex offender and suspicion of being made of crack.