石细胞

植物体内特别硬化的厚壁细胞.属于机械组织中的厚壁组织.石细胞分布广泛，种类多，形态各异.常呈圆形、椭圆形、丝毛状、分枝状、柱状、星芒状或骨状.次生壁极度增厚，而且木质化，有的栓化或角质化.有明显的同心环纹，具单纹孔.单纹孔在加厚的次生壁上呈沟状管道，多数汇合成分枝状态，与狭小的细胞腔连通.成熟后，石细胞的原生质体消失，成为有坚硬细胞壁的死细胞，有支持作用.石细胞常见于茎、叶、果实和种子中，单个散生或数个相聚.在梨的果肉中，桃、椰子的内果皮中，黄柏、黄藤的皮层中，白薇、三角叶黄莲的髓部，杜仲、厚朴、肉桂的维管束中均有石细胞分布.此外，在木犀和茶叶的叶肉常有单个生存的石细胞.大型石细胞呈“Ｔ”形、“Ｉ”形或星芒形.有大细胞腔的“滴漏细胞”、“柱细胞”为异型石细胞.石细胞在药材和木材鉴定上也有意义.Hardening of plants particularly thick-walled cells. Belonging to the thick-walled mechanical tissue organization. Stone cells are widely distributed and variety of different forms. Changchengnongxing round, oval, Silky-like, branch-like, columnar, Astral shaped or bone-like. secondary wall thickening of extreme, but lignification, some bolt-oriented, or horny. there is a clear concentric ring pattern, with a single pit. simple pits in the secondary wall thickening was in the groove shaped pipes, the majority of branches merge into the state, with small-cell cavities connected. mature, stone cell protoplasts disappearance of cell walls become hard and dead cells, there is a supporting role. stone cells commonly found in stems, leaves, fruit and seeds , a single or a few scattered together. in the flesh of pears, peach, coconut endocarp in, Treats, yellow vine of the cortex, Bai Wei, triangular leaves in silence of the hip, Eucommia ulmoides, Magnolia officinalis, Cinnamomum cassia and vascular in both the distribution of stone cells. In addition, osmanthus and tea leaf often the survival of a single stone cells. large stone cells were "T"-shaped, "I" shape or Astral-shaped. there are large-cell cavities of the "dropper cell" , "column cell" for the special-shaped stone cells. stone cells in the identification of medicinal plants, and wood is also significant.