名詞 cambium:

1. a formative one-cell layer of tissue between xylem and phloem in most vascular plants that is responsible for secondary growth
2. the inner layer of the periosteum

cam.bi.um

n.（名詞）
A lateral meristem in most vascular plants that forms parallel rows of cells resulting in secondary tissues either as secondary growth or as cork.
形成層：大多數(shù)導(dǎo)管植物中靠近邊緣的分生組織，它形成植物細(xì)胞組成的平行的行列，導(dǎo)致產(chǎn)生二次組織、二次增生或長成軟木

來源：
Medieval Latin [exchange]
中世紀(jì)拉丁語 [交換]
from Late Latin cambore, cambi3re [to exchange]
源自 后期拉丁語 cambore, cambi3re [交換]
[of Celtic origin]
[源于凱爾特語]

【引伸】
cam.bial
adj.（形容詞）