First, the disciplines are classified differently.
1, litchi
Litchi is a plant of Litchi in Sapindaceae.
2. Longan
Longan is a plant of Longan in Sapindaceae.
Second, the morphological characteristics are different.
1, litchi
Bark is gray-black, twigs are cylindrical, chestnut, and dense white lenticels. Thin leathery or leathery, lanceolate or ovate-lanceolate, sometimes elliptic-lanceolate, with a pointed or short-pointed tail, surrounded by dark green ventral surface, shiny back, pink green, and hairless on both sides; Lateral veins are often slender, the ventral side is not obvious, and the dorsal side is obvious or slightly convex.
Inflorescence terminal, calyx covered with short golden fluff, fruit ovoid to subglobose, usually dark red to bright red when mature; The seeds are all wrapped in fleshy arils.
2. Longan
Branchlets stout, puberulent, scattered pale lenticels. Thin leather, oblong elliptic to oblong lanceolate, often asymmetrical on both sides, short at the top, sometimes blunt, extremely asymmetrical at the base, wide wedge-shaped to truncated on the upper side, almost parallel to the leaf axis, narrow wedge-shaped on the lower side, dark green and shiny on the ventral side, green flour on the back, and hairless on both sides.
Inflorescence is large, multi-branched, terminal axillary, petals milky white, lanceolate, nearly as long as sepals, fruit nearly spherical, usually yellowish brown or sometimes grayish yellow, seeds dark brown, shiny, all wrapped by fleshy arils.
Third, the growth environment is different.
1, litchi
Litchi trees like high temperature and humidity and sunshine. Its heredity requires that the temperature of flower bud differentiation is relatively low, but the lowest temperature is -2 ~-4℃, so they will suffer from freezing injury. It is sunny and warm in flowering period, and no dry heat is the most favorable. Too low humidity, continuous rain, dry and hot weather or strong north wind are not conducive to flowering and pollination. Unfavorable disaster weather in the flower and fruit period will lead to falling flowers and fruits, and even loss of harvest.
2. Longan
Longan grows in the south subtropical region and needs plenty of sunshine. I like warm and humid climate, can endure short-term frost, and won't freeze to death in a short time at low temperature of 0-4℃. Longan has strong adaptability to soil. As long as the topsoil is deep and well drained, almost all kinds of soil can adapt.
Refer to the above? Baidu encyclopedia-litchi, Baidu encyclopedia-longan