vascular cambium

Multiple cross sections of a stem showing vascular cambium and companion cells^[1]

The vascular cambium is a lateral meristem in the vascular tissue of plants. The vascular cambium is the source of both the secondary xylem (inwards, towards the pith) and the secondary phloem (outwards), and is located between these tissues in the stem and root. A few leaf types also have a vascular cambium.^[2]

The vascular cambium usually consists of two types of cells:

• Fusiform initials (tall cells, axially oriented)
• Ray initials (almost isodiametric cells - smaller and round to angular in shape)

The vascular cambium is a type of meristem - tissue consisting of embryonic (incompletely differentiated) cells from which other (more differentiated) plant tissues originate. Primary meristems are the apical meristems on root tips and shoot tips. Another lateral meristem is the cork cambium, which produces cork, part of the bark.

Vascular cambia are found in dicots and gymnosperms but not monocots, which usually lack secondary growth.

For successful grafting, the vascular cambia of the stock and scion must be aligned so they can grow together.

Synonyms

• Wood cambium
• Main cambium
• Bifacial cambium

References

1. ^ Winterborne J, 2005. Hydroponics - Indoor Horticulture [1]
2. ^ Ewers, F.W. 1982. Secondary growth in needle leaves of Pinus longaeva (bristlecone pine) and other conifers: Quantitative data. American Journal of Botany 69: 1552-1559. [2]

See also

• Meristem
• Cork cambium
• Unifacial cambium
• Sun scald (flora)

External links

• Pictures of Vascular cambium
• Detailed description - James D. Mauseth