Nine-bark
Nine´-bark`
n. | 1. | (Bot.) A white-flowered rosaceous shrub (Neillia opulifolia, or Spiræa opulifolia), common in the Northern United States. The bark separates into many thin layers, whence the name. |
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.