She's a Hollywood A-lister, with a mantelpiece groaning under the weight of awards. But Cate Blanchett has taken an unexpected diversion from her day job - to immerse herself in the world of the humble seed. Her eyes light up as she enthuses about the banksia species from her native Australia. "It's quite a brutal looking seed pod that only releases its seed in extremely high temperatures," she tells us. "It does look like a cross between a mallet and a toilet brush. So they're not always