pith

noun

1. the choicest or most essential or most vital part of some idea or experience

e.g. the gist of the prosecutor's argument
the heart and soul of the Republican Party
the nub of the story

Synonym: kernelsubstancecorecentercentreessencegistheartheart and soulinwardnessmarrowmeatnubsumnitty-gritty

2. soft spongelike central cylinder of the stems of most flowering plants

verb

1. remove the pith from (a plant)

1. （柑橘类水果皮和瓤之间的）衬皮
The pith of an orange, lemon, or similar fruit is the white substance between the skin and the inside of the fruit.

1. 髓心：树木因周期性的生长,而在其横断面围绕著髓心(pith)形成同心圆状的木质部层次,我们叫它为生长层(growth layer),其断面称为生长轮(growth ring). 在暖温地带所生长之树木,因四季较为分明,通常一年仅具有一个生长周期,

2. pith

2. 髓：4薄壁组织(parenchyma)-- 由中柱内的薄壁细胞组成;位于初生木质部与初生韧皮部之间的,称木、韧间薄壁细胞,形成维管形成层的大部分;有些植物根的中柱中央也有薄壁细胞,称为髓(pith)

3. 木髓：resin 树脂 | pith 木髓 | cambium 形成层

4. 树心：横锉法 crossfiling | 树心 pith | 树皮 bark