Joan Rivers, Theatre Royal, Glasgow

For those un-versed in the garish stage persona of Joan Rivers - particularly British audiences for whom her heyday as the queen of US talk-show television is a mystery - it's initially hard to establish whether she's telling the jokes, or is the joke.

Even a master of character sitcom such as Larry David or Steve Coogan would be hard pressed to conjure a creation as larger-than-life as Rivers. With a face artificially enhanced by years of plastic surgery, a sharp Brooklynite's yelp, and a pair of vicious high heels which send her careering around the stage in a particularly unsteady fashion, she presents the façade of a bitchy, somewhat superannuated, Hollywood harridan to perfection.

Exactly how much of this persona is Rivers' own is hard to divine, although the best part of four decades at the sharp end of the wedge as an American television star, and those famously reconstructed features, are testament to the fact that she's firmly entrenched in the world she typifies. Yet Rivers learnt her trade as a stand-up in the coffee houses of Greenwich Village back in the 1950s, and the fact that the now-71-year-old can still deliver as manic an hour of cutting, topical, funny material as this is evidence of a keen and manipulative comedy mind still very much at work.

Everyone is potentially in receipt of her indignant, catty fury, from sacred cows to the front row, and even herself. The warm-up act Kit and The Widow - an upper-crust English duo with a hint of Fry and Laurie about them - even get to poke questionably charitable fun at their benefactor. Her dressing room, we were told, is like Frankenstein's laboratory.

Such authorised barracking does tend to sink our image of the onstage Rivers as a demanding prima donna, a perception further eroded once she takes her first bow. It takes her about three minutes to first mention that she's Jewish, a fact that places the former Joan Molinsky (the daughter of Russian immigrant parents) alongside a rich entertainment tradition in the States, but which means very little to a Scots crowd. To them she's just a mouthy, larger-than-life New Yorker, albeit now one with the perceived right to tell jokes about the Second World War. A moment occurs when Rivers relates watching Germans taking part in their national parade down Fifth Avenue. All blonde-haired, blue-eyed and handsome, she recalls: if she were Anne Frank she would have been calling, "I'm in the attic". Yet this gag itself comes from a sequence about realising that every race or individual lives up to their stereotype. It's implicit that she's talking about herself here, that she knows she's a kind-of-trashy showbiz dame, and she's unashamed of it.

Making further contentious cracks about whether a long-married woman would rather have $6m compensation or the husband she lost in the World Trade Centre might raise a pained expression from some, but many comics half her age would be too nervous to even air it. She might be easy to like, but it's this boldness which wins her the respect she deserves.