Want to know more about stems?
click the folder below

A work by group 1

external parts

  • Nodes: area or region of a stem where a leaf or leaves are attached.

  • Internodes: stem region between nodes

  • Petiole: a stalk that serves as an attachment of the leaf to the twig Axil: the angle between a petiole and the stem

  • Axillary bud: bud located in the axil

  • Bud Scales: It protects the buds Terminal Bud: It is a little larger than the axillary bud; do not become separate branches

  • Stipules: paired, often somewhat leaflike, appendages that may remain throughout the life of the leaf

  • Lenticels: these are porous, raised spots on woody stems, roots, and some fruits (like apples, potatoes) that function as crucial pores for gas exchange.

Internal parts

  • Pith: The central core, often for storage, which can be solid or hollow.

  • Cortex: It's mainly made of parenchyma cells, responsible for storing food and, providing support

  • Vascular cambium: is responsible for the secondary growth in plant stem, hypocotyl, and root tissues.

  • Cork cambium: woody species; arises within the cortex, produces box-like cork cells which are impregnated with suberin (waxy substance that makes the cell impervious to moisture

  • Epidermis: forms a protective outer layer on stems (and other parts), preventing water loss and infection

  • Xylem: Transports water and dissolved minerals from roots to stems and leaves

  • Phloem: Transports sugars (food), amino acids, and hormones from leaves to other plant parts

Monocot Stems (MONOCOTYLEDON STEMS)

  • These stems have usually large hollow vessels elements and no secondary growth.

  • They are characterized by scattered vascular bundles throughout the stem, while lacking of TRICHOMES, PERICYLE, , MEDULLARY RAYS, LESS DEVELOPED PITH/ CORTEX, stele and cambium.

  • In the monocot stems, the phloem are oriented towards outside of the plant, the xylem towards inside.

  • The vascular bundles are surrounded by a layer of parenchyma cells or called a bundle sheath and are arranged throughout the ground tissue in concentric circles.

  • Examples are rice, corn, wheat, sugarcane, bamboo

Dicot Stems (DICOTYLEDONOUS Stems)

  • Vascular bundles are arranged in a ring around the circle of the plant stem

  • The cortex is oriented outside while the pith inside.

  • The presence of pericycle, cambium, medullary rays and secondary growth and a well developed cortex and pith

  • Examples are bean, pea, mango, sunflower, rose

References