Possible Clues:

• Speed salad plant absorbs it
• Star lacking core providing speed
• The speed in which it takes on vegetable form
• Salad food absorbs it with speed
• The rapidity with which a famous person loses heart
• The speed of fame -- not British
• Stick it inside for dispatch
• Heartless star's expedition
• Pace had famous sportsman perhaps bowled out
• With speed it has burrowed into the vegetable