Probably because he is just as difficult to get rid of as the hardy Central Otago plant.
But Grant Sanders believes he is just plain lucky.
Mr Sanders remembers little about the crash, which nearly claimed his life shortly after noon on Friday.
The 63-year-old was the sole occupant of his Nissan Atlas truck when it plunged off Little Valley Rd, above Alexandra's clock on the hill, and plummeted 50m down a bank before landing in an old water race.
''The truck rolled over about four times. Another half a roll and I'd have gone down another 70m. Someone's on my side,'' he mused from his bed at Dunedin Hospital yesterday.
''I know that country like the back of my hand, because I used to muster up there. The load on the truck must have shifted, because all I remember is the truck lurching to one side.''
He was trapped in the overturned truck for up to an hour and a-half, before he managed to call for help.
''I don't know how long I was there for, but I was lucky the cellphone was in my top pocket and I could put in a call. It was also lucky I had cellphone coverage,'' he said.
Mr Sanders is well known in Central Otago through his involvement with the Otago Goldfields Heritage Trust Cavalcade, Alexandra Blossom Festival and Alexandra Lions Club.
So he knew the 20 emergency services personnel who assisted with the two-and-a-half-hour rescue.
''I remember someone saying: 'Tussock, we didn't recognise you without your hat on','' he said with a chuckle, before grimacing with pain from his broken ribs.
''They thought I'd broken my legs at first. My right leg was jammed between the dash and the driver's door.''
He was airlifted to Dunedin Hospital by the Otago Regional Rescue Helicopter, with chest and leg injuries.
''I heard the helicopter pilot say on the radio that we'd be there in 28 minutes and I thought: 'That's marvellous'. It's incredible the way they can pick you up right from the spot.''
