Several fruit trees, such as various kinds of citrus fruit which flourish in U.S. Department of Agriculture plant hardiness zones 9 through 11, have thorns on their divisions. The thorns will be the tree’s way of protecting itself against starving animals that are looking to nibble on the leaves and fruit of the tree, that may heavily damage or even destroy a young tree. With the years, as the tree grows older and stronger — and much better able to take care of creature damage — the thorns generally diminish.
Lemon (Citrus limon) is the top acidic citrus fruit, according to Purdue University Agriculture. Desirable for its distinctive odor and taste, it is cultivated in tropical and subtropical climates around the world. Most accurate, or species, lemon trees possess sharp thorns lining the invading. Several hybrid varieties, however, are almost thornless, like “Eureka,” that is a top cultivar in California.
Oranges (Citrus sinensis) are loved around the world for their attractive package and sweet taste, though some are much sweeter than others. With the years, growers have bred oranges to be less thorny. Today, most varieties are thornless or possess thin, dull, elastic thorns found just at the base of their leaves. Oranges which are bitter and never commonly consumed, however, may have big thorns. The hardy or trifoliate orange tree, as an instance, features sharp, 2-inch extended thorns and sour fruit.
Limes (Citrus aurantifolia) are used in everything from cooking to adding fragrance to cleansers and other industrial products. They’re the 2nd most popular acidic citrus fruit — secondly to lemons — and will also be less cold-hardy than lemons. Although lime trees, using their small, stocky profile along with thorny branches, look somewhat tough, the fruit is in fact sensitive to coldtemperatures. Most commercially valuable lime trees do possess small thorns, and even though thornless varieties are more desirable, they are less productive, according to Texas A&M; Aggie Horticulture. The Mexican lime, or the important lime, is probably the most well-known of the varieties.
Grapefruit (Citrus X paradisi) trees, such as other citrus trees, have thorns, but they’re short and flexible, and they’re only found on the twigs. “Marsh” is the most popular variety grown in the United States and is desirable for its sweet, juicy flesh and small amount of seeds.
Kumquats (Fortunella spp.) , included in the Citrus genus until 1915 when they were reclassified to the Fortunella genus, are prized for their sweet and tart flavor — the thin, creamy skin is sweet, but the pulp is tart. Kumquats are all about the size of plums, with skin which range from bright orange to ruby red, and are generally eaten whole. The trees are small, compact and slow-growing. Many, like “Hong Kong,” are liberally covered with thorns. A few others, like the popular “Meiwa,” are thornless or feature small — but still sturdy — spines.