Q.There are many tissues produced outside the vascular cambium in the stem. Explain them

Step 1. Recall the definition of bark. The chapter defines bark as the term commonly applied to all the tissues outside the vascular cambium of a stem - specifically the periderm, the cortex, the primary phloem and the secondary phloem.

Step 2. Explain the periderm's three layers. The periderm itself, the outermost protective unit, is built by the cork cambium (phellogen) and consists of three parts: phellogen, the actively dividing meristem itself; phellem (cork), the dead, suberised protective layer it cuts off outward; and phelloderm (secondary cortex), the living, parenchymatous layer it cuts off inward.

Step 3. Explain the phloem tissues. Secondary phloem (bast) is produced continuously on the outer face of the vascular cambium and conducts food; primary phloem, formed earlier during the stem's primary growth, is progressively crushed as secondary phloem accumulates outside the cambium, but its (crushed) remains are still counted as part of the bark, outside the cambium, until it is finally used up. …

List and briefly describe each tissue lying outside the vascular cambium - periderm's three layers, remnant cortex, and primar …

• Naming only the periderm and forgetting that primary and secondary phloem are also outside the vascular cambium and are also part of the bark. …