What are the names of the tubes through which organic matter flows? Describe their structure

Higher plants have different tissues in their structure. Among them are conductive or transport tissues. They are necessary for the transport of various substances. Water and mineral salts pass through the vessels. These are dead conductive cells. Organic matter is transported from the photosynthetic parts of the plant through sieve tubes. They are already living cells. They have an elongated shape. Also, they lack a nucleus and many other organelles so as not to interfere with the passage of organic matter through these tissues.