Phellogens Sentence Examples
Eventually the new phellogens reach the level of the secondary phloem, and are formed in the parenchyma of the latter, keeping pace in their inward march with the formation of fresh secondary phloem by the cambium.
The rough surface of the bark of many trees is due to the successive phellogens not arising in regular concentric zones, but forming in arcs which join with the earlier-formed arcs, and thus causing the bark to come off in flakes or thick chunks.
In such stems and roots as increase in thickness there are other growing regions, which consist of cylindrical sheaths known as cambium layers or phellogens.
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