Yep, one frosty morning about a decade ago I was doing a predawn creek side trail on one of the eastern US battlefield national parks. As I approached a bend I heard a huge ker-PLUNGE. Hmmmm, maybe a big critter jumped in. Then another and another. I'm now thinking somebody is messing with me so I stop to watch in the dark. Turns out the frost had loosened the stems and they were falling off en mass as I passed.

Hedgeapples are the fruit of Osage Orange which were brought east from the Mississippi drainage to form living cattle hedges 'cause they grow fast and have spines. The roots are bright orange. Even goats won't eat 'em. They're a scourge clogging floodplains in the eastern US. http://en.wikipedia.org/wiki/Osage-orange