Botany - B.Ye. Yakubenko 2017
Part One. Plant Anatomy and Morphology
Chapter II. Histology
2.1. Plant Tissues and Their Classification
In multicellular plants, Cell Division and differentiation lead to The formation of complex structures. A group of interconnected Cells that share a common origin, Structure, and function is called a tissue.
Tissues make up Organs, and organs make up the bodies of higher plants. In this context, tissues can be viewed as structural units of a multicellular Organism. They are interconnected and ensure the integrity of the organism as a whole.
Plant tissues are groups of cells held together by intercellular substance, which was discovered in the early 19th century by P. Moldenhauer. The first attempts to classify plant tissues were made by N. Grew, who distinguished between parenchymatous and prosenchymatous tissues.
Later, attempts were made to classify tissues based on their function. Today, the physiological Classification is combined with the morphological one. This combined physio-morphological classification is the most thoroughly developed and widely accepted. According to this system, all tissues are divided into six main groups: meristematic (or Meristems) and permanent tissues, which include protective, mechanical (or strengthening), conducting, fundamental, and Secretory Tissues. (Table 2)
Class="center">Table 2. Classification of plant tissues
|
Tissue type |
Tissue subtypes |
Tissue kinds |
Location (localization) in the plant |
|
I. Meristematic (meristems) |
1. Apical 2. Lateral 3. Intercalary 4. Wound (traumatic) |
Tunica and corpus; Dermatogen, periblem, plerome Primary: procambium, pericycle. Secondary: cambium, phellogen |
SHOOT apex Tip of a young ROOT Axial organs (stem, root) Axial organs (stem, root) Above cereal nodes, at the base of floralscapes, leaves. At sites of organ injury |
|
II. Protective |
1. Primary 2. Secondary 3. Tertiary |
Epidermis Epiblem (rhizodermis) Cork (phellem) Bark (rhytidome) |
Leaves, stems of young plants, floral parts Young roots Roots of dicots and stems of woody plants Stems of woody plants |
|
III. Fundamental |
1. Assimilation (chlorenchyma) 2. Storage 3. Aerating 4. Water-storing 5. Absorbing |
Palisade (parenchyma), Spongy Plicate Endosperm Perisperm Storage parenchyma Aerenchyma Water-storage parenchyma Epiblem with root hairs |
Beneath the upper epidermis of a dorsiventral leaf Below the palisade layer in a flat leaf Needle-like and scale-like leaves Seeds Seeds All plant organs Mostly in aquatic and marsh plants Leaves and stems of succulents Young roots |
|
IV. Conducting |
1. Water-conducting 2. Nutrient-conducting |
Tracheids Vessels (tracheae) Sieve tubes Companion cells |
In all plant organs, as part of the xylem In all plant organs, as part of the phloem |
|
V. Mechanical |
1. Collenchyma 2. Sclerenchyma 3. Sclereids |
Angular Lamellar Lacunar Bast fibers Libriform fibers Sclerenchyma fibers Stone cells (sclereids) Supporting cells |
In leaves and stems of dicotyledonous plants Mostly in stems of dicotyledonous plants Part of the phloem Part of the xylem In all organs In all organs |
|
VI. Secretory |
1. External secretion 2. Internal secretion |
Glandular trichomes Glandular scales Nectaries Hydathodes Schizogenous and lysigenous cavities Resin ducts Laticifers |
Leaves, stems, flowers Inside all plant organs |
Last update: 07/08/2026
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