The leaves of mitragyna speciosa, like all leaves of angiosperms, have veins running through them to deliver water and minerals to the leaves so that they can grow to their full size, thereby maximizing the process of photosynthesis. And much has been said about the veins of kratom plants, with people differentiating between the coveted red vein, korth strain and those with white veins.
In biological terms, the veins of all leaves, including kratom veins, are the vascular tissue of the leaf, providing strength and support for the surface of the leaf. They are located in the spongy layer of the mesophyll, and the patterns they assume in the leaf are referred to as “venation.” Each vein has two parts. First, the xylem, which bring water and minerals from the root to the kratom leaf. Second is the phloem, which moves the products of photosynthesis (dissolved sucrose) from the leaf to the tree’s central structure.
In his seminal report of addiction among native users of kratom, “A Study of Kratom Eaters in Thailand” (Bulletin on Narcotics, 1975; Vol. 27(3): 21-27), Sangun Swanlert distinguished between those who chewed red vein and white vein kratom. According to him, the white veined kratom has a stronger effect, though this distinction seems based on little more than folklore. Swanlert offers no breakdown of alkaloid content of the two Mitragyna speciosa varieties, thus his distinction is based on reports of those surveyed. Among them, Swanlert found that the majority of his sample group preferred a mixture of red and white veined kratom. Potential explanation for why they preferred this mixture is left unexplored. Perhaps it was merely a natural human desire for variation, or perhaps it was purely aesthetic. Among those who favored one color vein over the other, red veined kratom was the more popular.