Pithy

a.
  1. Consisting wholly, or in part, of pith; abounding in pith; as, a pithy stem; a pithy fruit.
  2. Having nervous energy; forceful; cogent.
    3. Pithy gall (Zoöl.),
    a large, rough, furrowed, oblong gall, formed on blackberry canes by a small gallfly (Diastrophus nebulosus).