2. Structure and development of Shoot apex 茎尖结构与发育
Morphology of shoot apex 茎尖形态学
腋芽 原基
叶原基 原形成层
生长锥 （顶端 分生组织）
基本分生组织
叶迹
腋芽 原基
叶隙
The tunica-corpus organization of the apical meristem. 茎尖分生组织的原套---原体结构
Outer characters on the
stem of Carya （胡桃）
Stem morphology of a gymnosperm 裸子植物茎外形
叶座 芽鳞痕 （年痕）
Annual growth
Stem of a gymnosperm, fir (Abies sp.) 冷杉, showing circular scars that mark the sites of leaf attachment (叶座）.
Sympodium branching 合轴分枝
False dichotomous branching 假二叉分枝
Dichotomous branching 二叉分枝, 见于蕨类植物，是一种 较原始的分枝方式
Tiller of grass ( Poaceae) 禾本科草的分蘖
1. 种子; 2. 分蘖节; 3.不定根
Long shoots and short shoots 长枝与短枝
Long shoot and short shoot of Ginkgo biloba 银杏的长短枝
Branching of stems 茎的分枝 Monopodial branching 单轴分枝
Branching of stems 茎的分枝
tunica (identify them). 成皮层、维管束、髓、射线
The tunica-corpus and tissues theory of the apical meristem 茎尖分生组织的原套---原体及组织学说
中央母细胞
周围分生组织
髓分生组织 （肋状分生组织）
髓分生组织 （肋状分生组织）
洋葱的鳞茎---变态地下茎
马铃薯的块茎---变态地下茎
Modified belowground stems often help plants survive cold winter. 变态的地下茎使植物度过寒冷的冬季。
Different types of buds 芽的不同类型
Bud morphology under SEM 扫描电镜下的芽外型
Note the cell wall
orientations in the
corpus (C) as opposed to
the strictly anticlinal （垂
周）wall orientations
that occur in the tunica
(T). The initials of the
茎连接根和叶，茎由四种组织 构成：表皮、维管组织、基本 组织和分生组织
1. Morphology of Stem 茎的形态
Morphology of an angiosperm stem 被子植物茎外形
顶芽
叶痕
Node 节
Internode 节间
维管束痕 （叶迹）
芽鳞痕 （年痕）
芽鳞痕 （年痕）
The stem tip on the left shows the terminal bud (TB), leaf scars (LS), vascular bundle scars (VB) within the leaf scars, and annular scars (AS) . The right-hand picture shows an ash stem at lower magnification with two annual rings as indicated by arrows.
Echeveria, 石莲花的茎很短
香蕉的茎是由一系列互相重叠的叶柄 组成的
葫芦科的攀缘茎---卷须
竹节蓼的叶状茎
Modified stems(变态 一种永叶菊属的丛生叶长在伸长的茎上 茎）adapt plants to
different factors in the environment.
变态茎---草莓的匍匐茎 变态茎---爬山虎的茎吸盘
The tunica-corpus and tissue theory of the apical meristem. 茎尖分生组织的原套---原体及组织学说
Chapter Four
Structures and development of Plant Organs
植物的器官的结构与生长发育
Section 3 Morphology, structure and development of stems 第三节 茎的形成、结构及生长发育
Stems are a important link between leave and roots. Stems are composed of the four kinds of tissues found in all organs of a plant: epidermis, vascular, ground, and meristematic tissues.
tunica divide anticlinally
only, while the initials of
the corpus also divide
periclinally（平周）. This 注意：原套（T)细胞壁方向，以后
specimen appears to
发育成表皮、皮层
have three cell layers of 原体（C)细胞壁方向，以后发育
Annual growth from buds is representbranches.
Different habits of stem 茎的不同习性
左
右
Different habits of stem 茎的不同习性 Stems play key roles in the ecology of plants