Title: Sieve tube element
Content:  are specifically related to the sieve tube elements. Sieve tube members and companion cells are connected through plasmodesmata. Plasmodesmata consists of channels between cell walls of adjacent plant cells for transport and cell to cell recognition. Structurally, the walls of sieve tubes tend to be dispersed with plasmodesmata grouped together and it is these areas of the tube walls and plasmodesmata that develop into sieve plates over time. Sieve tube members tend to be found largely in angiosperms. They are very long and have horizontal end walls containing sieve plates. Sieve plates contain sieve pores which can regulate the size of the openings in the plates with changes in the surroundings 
Title: Phloem
Content: 1) Ordinary companion cells, which have smooth walls and few or no plasmodesmatal connections to cells other than the sieve tube. ; 2) Transfer cells, which have much-folded walls that are adjacent to non-sieve cells, allowing for larger areas of transfer. They are specialized in scavenging solutes from those in the cell walls that are actively pumped requiring energy. ; 3) Intermediary cells, which posses many vacuoles and plasmodesmata and synthesize raffinose family oligosaccharides. The metabolic functioning of sieve-tube members depends on a close association with the companion cells, a specialized form of parenchyma cell. All of the cellular functions of a sieve-tube element are carried out by the (much smaller) companion cell, a typical nucleate plant cell except the companion cell usually has a larger number of ribosomes and mitochondria. The dense cytoplasm of a companion cell is connected to the sieve-tube element by plasmodesmata. The common sidewall shared by a sieve tube element and a companion cell has large numbers of plasmodesmata. There are three types of companion cells.
Title: Sieve tube element
Content:  Sieve cells are long, conducting cells in the phloem that do not form sieve tubes. The major difference between sieve cells and sieve tube members is the lack of sieve plates in sieve cells. They have a very narrow diameter and tend to be longer in length than sieve tube elements as they are generally associated with albuminous cells. Similar to how Sieve Tube members are associated with companion cells, sieve cells are flanked with albuminous cells in order to aid in transporting organic material. Albuminous cells have long, unspecialized areas with ends that overlap with those of other sieve cells and contain nutrients and store food in order to nourish tissues. 
Title: Phloem
Content:  [[File:Phloem and Xylem in stem.svg|thumb|Simplified phloem and companion cells: 1. Xylem 2. Phloem 3. Cambium 4. Pith 5. Companion cells]] Sieve elements are the type of cell that are responsible for transporting sugars throughout the plant. At maturity they lack a nucleus and have very few organelles, so they rely on companion cells or albuminous cells for most of their metabolic needs. Sieve tube cells do contain vacuoles and other organelles, such as ribosomes, before they mature, but these generally migrate to the cell wall and dissolve at maturity; this ensures there is little to impede the movement of fluids. One of the few organelles they do contain at maturity is the rough endoplasmic reticulum, which can be found at the plasma membrane, often nearby the plasmodesmata that connect them to their companion or albuminous cells. All sieve cells have groups of pores at their ends that grow from modified and enlarged plasmodesmata, called sieve areas. The pores are reinforced by platelets of a polysaccharide called callose.
Title: Sieve tube element
Content:  There are two categories of sieve elements: sieve cells and sieve tube members. The main functions of sieve tube members include maintaining cells and transporting necessary molecules with the help of companion cells. The sieve tube members are living cells (which do not contain a nucleus) that are responsible for transporting carbohydrates throughout the plant. Sieve tube members are associated with companion cells, which are cells that combine with sieve tubes to create the sieve element-companion cell complex. This allows for supply and maintenance of the plant cells and for signaling between distant organs within the plant. Sieve tube members do not have ribosomes or a nucleus and thus need companion 
Title: Sieve tube element
Content:  enable the sieve cells to be connected to parenchyma, functional tissue in the organs, which helps to stabilize the tissue and transport nutrients. Sieve cells are also associated with gymnosperms because they lack the companion cell and sieve member complexes that angiosperms have. Sieve cells are very uniform and have an even distribution across of sieve areas. Their narrow pores are necessary in their function in most seedless vascular plants and gymnosperms which lack sieve-tube members and only have sieve cells to transport molecules. While sieve cells have smaller sieve areas, they are still distributed across several cells to still effectively transport material to various tissue within the plant. Sieve cell associated 
Title: Tissue (biology)
Content:  cytoplasm extends from cell to cell. These porous connections are called sieve plates. In spite of the fact that their cytoplasm is actively involved in the conduction of food materials, sieve-tube members do not have nuclei at maturity. It is the companion cells that are nestled between sieve-tube members that function in some manner bringing about the conduction of food. Sieve-tube members that are alive contain a polymer called callose, a carbohydrate polymer, forming the callus pad/callus, the colourless substance that covers the sieve plate. Callose stays in solution as long as the cell contents are under pressure. Phloem transports food and materials in plants upwards and downwards as required.
Title: Sieve tube element
Content:  for cytoplasmic connections to neighboring cells, which allows for the movement of photosynthetic material and other organic molecules necessary for tissue function. Structurally, they are elongated and parallel to the organ or tissue that they are located in. Sieve elements typically lack a nucleus and contain none to a very small number of ribosomes. The two types of sieve elements, sieve tube members and sieve cells, have different structures. Sieve tube members are shorter and wider with greater area for nutrient transport while sieve cells tend to be longer and narrower with smaller area for nutrient transport. Although the function of both of these kinds of sieve elements is the same, sieve cells are found in gymnosperms, non-flowering vascular plants, while sieve tube members are found in angiosperms, flowering vascular plants. 
Title: Plant cell
Content:  Phloem is a specialised tissue for food transport in higher plants, mainly transporting sucrose along pressure gradients generated by osmosis, a process called translocation. Phloem is a complex tissue, consisting of two main cell types, the sieve tubes and the intimately associated companion cells, together with parenchyma cells, phloem fibres and sclereids. Sieve tubes are joined end-to-end with perforated end-plates between known as sieve plates, which allow transport of photosynthate between the sieve elements. The sieve tube elements lack nuclei and ribosomes, and their metabolism and functions are regulated by the adjacent nucleate companion cells. The companion cells, connected to the sieve tubes via plasmodesmata, are responsible for loading the phloem with sugars. The bryophytes lack phloem, but moss sporophytes have a simpler tissue with analogous function known as the leptome. 
Title: Sieve tube element
Content:  Sieve elements are specialized cells that are important for the function of phloem, which is a highly organized tissue that transports organic compounds made during photosynthesis. Sieve elements are the major conducting cells in phloem. Conducting cells aid in transport of molecules especially for long-distance signaling. In plant anatomy, there are two main types of sieve elements. Companion cells and sieve cells originate from meristems, which are tissues that actively divide throughout a plant's lifetime. They are similar to the development of xylem, a water conducting tissue in plants whose main function is also transportation in the plant vascular system. Sieve elements' major function includes transporting sugars over long distance through plants by acting as a channel. Sieve elements elongate cells containing sieve areas on their walls. Pores on sieve areas 

Question: name the cell which is attached to the lateral side of sieve tube?
Answer: sieve tube elements.