What are the chances of getting a nice cup of herbal tea at a Green Party annual meeting these days?

Not good, as it turned out over the weekend at Pt Chevalier's Te Mahurehure Marae. What's more, the lunch on offer from the Greens included much in the way of familiar comfort food including ham sarnies and even sausage rolls.

Yes, there were bean sprouts, but they're pretty much mainstream fare too these days.

As are a number of Green policies. Watered down as it is, the ETS is some form of response to the threat of climate change. And National has implemented the Greens' home insulation, pest control and contaminated site clean-up programmes.

Meanwhile the party's younger crop of MPs, candidates and staffers, including Metiria Turei and Russel Norman, appear to be making at least some progress in exorcising the popular caricature of the Greens as bearded folk dancing, pot-smoking luddites with policies based on no more than a foggy comprehension of real economics.

Sure there were plenty of folks who might fit the old stereotype, but there seemed to be a higher proportion - even than at last year's AGM - of younger types who looked as though they could work for a bank.

At least some of them still do.

New arrival at number 15 on the party list James Shaw makes enough dough working overseas for half a year at a time as a management consultant for the likes of BP, Amex and Coca-Cola to sustain himself while working the rest of the year for the Greens.

One imagines that doesn't endear him to the likes of the party member who yelled "class traitor" at the mention of Social Development Minister Paula Bennett during Ms Turei's speech.

That speech saw the announcement of the Greens' decision they may consider a formal coalition with National. A "highly unlikely" prospect to say the least, but a change from previously ruling it out altogether.

The decision and its stage management is as much a message to Labour not to treat the Greens shabbily as it has in the past as it is a bid to portray the party as a "constructive" political entity rather than extremist. All of this was, said Ms Turei, about being honest with voters, but you couldn't blame them for wondering exactly what was going on.

Even as the Greens were opening the door to National, Ms Turei said it would take an extreme shift in National's economic environmental and social policies before that happened.

All of this has a whiff of the Machiavellian for a party sometimes seen as self-defeatingly nice. While the Electoral Commission recently promoted the Greens from the ranks of the "small" parties to "medium" status, it's hard to imagine them stooping to grubby politics as their big party rivals often do.

But at the very least they are showing signs of developing a more cunning approach to advancing their cause.

As the bard of the generation of Green MPs who took the party into Parliament but who will be gone after the November election put it, "the times they are a changing".