I like Grevilleas because of their pollination mechanism. At first the stigmas are trapped in the heads of the anthers, so the pistil forms a loop. Once the floret is 'ripe', when a bee visits, the insect triggers the realease of the stigma, which bangs the insect on the head shooting pollen all over it. Only after that does the stigma become ready to receive pollen (that encourages cross pollination). In your picture most of the pistils have straightened out (been triggered), but there are a few younger florets (in the middle of the flower) with pistils that are still looped.