Why do many Malvales plants have fibrous or stringy bark?

Many plants within the Malvales order possess stringy or fibrous bark because of the presence of distinct bands of fibers located in the phloem, which is the tissue situated just outside the wood.2

These fibers, often referred to as bast fiber, are composed of cellulose-rich sclerenchyma cells. In the secondary phloem of these plants, these fibers typically occur in clusters or alternating bands alongside sieve tubes and parenchyma cells. This structural arrangement provides the bark with its characteristic toughness, flexibility, and fibrous texture. Because of these durable qualities, the inner bark of various Malvales species has historically been valued for practical applications such as the production of cordage, ropes, and coarse netting.1234