tunica
/ˈtjuːnɪkə/noun
(pl. tunicae /-kiː/)
1
- Anatomy a membranous sheath enveloping or lining an organ【剖】膜, 被膜。
2
- Botany the outer layer or layers of cells in an apical meristem, which contribute to surface growth【植】原套。
词源
late 17th cent.: from Latin, literally 'tunic'.