Possible Clues:

• Swede: 'I go before end of cup'
• Large yellow or white edible root
• Vegetable grown underground
• The root of pi? That may be how you get to it
• The way to get to the root of pi?
• Type of greens
• Sounds as if one might arrive at the root of this
• To get to the root of this, pin up the groove
• Vegetable in pot found in rubbish dump
• Plant with round white root used as vegetable