Q.Phloem fibres are called as:

Phloem (term coined by Nageli, 1858; older synonym leptome, Haberlandt 1914) is the complex food-conducting tissue of vascular plants, built from four cell types: sieve elements, companion cells, phloem parenchyma and phloem fibres. Phloem derived from procambium is primary phloem, whose early-formed protophloem elements are short-lived and get crushed as the later-formed metaphloem develops around them; phloem derived later from vascular cambium is secondary phloem. Sieve elements, the actual conducting cells, occur in two forms: sieve cells, the more primitive type, with sieve areas that are not well differentiated and never organised into distinct plates, no associated companion cells, and found in pteridophytes and gymnosperms (where their activity is instead regulated by nucleated albuminous cells - also called Strasburger cells - the functional analogue of a companion cell); and sieve tubes, files of sieve-tube elements placed end to end and connected at well-differentiated sieve plates bearing fewer but larger sieve pores, each paired with its own nucleated companion cell, and found only in angiosperms. Companion cells are living, narrow, nucleated cells connected to their neighbouring sieve-tube element by plasmodesmata, co …