Possible Clues:

• Number exercise, cut off in part of plant
• A number do military exercises, we’re told, or shoot
• All fingers and thumbs we hear training part of plant
• Clinging part of ivy
• Look after both sides holding current shoot
• Catch up with endlessly training part of plant
• 'The Thing' limb
• Threadlike part of a climbing plant
• Slender stem-like structure used by some climbing plants
• Wall-climbing aid