The Complete and Latest Guide to Cactus: Everything You Need to Know in One Article

Cactus is also known as Xianbazhang, Bawangshu, Huoyan, Huozhang, Niushedou, and so on. It is a clustered succulent shrub of the genus Opuntia in the family Cactaceae, with a great many species. Worldwide there are 70 to 110 genera and more than 2000 species, which can be specifically divided into the pad-forming cactus group, the segmented cactus group, the crab claw cactus, the leaf-type forest cactus group, the globular cactus group, and so on. It often grows in dry environments such as deserts and is called the “hero flower of the desert”, and it is a type of succulent plant.

Cactus grows 1.5 to 3 m tall. The upper branches are broadly obovate, obovate-elliptic, or nearly circular, with edges usually irregularly wavy, the base cuneate or gradually narrowed, green to blue-green, and hairless. The areoles are sparsely borne and clearly protruding; as they grow, the spines often thicken and increase in number, with each areole bearing 3 to 10 spines, densely covered with short woolly hairs and barbed bristles. The spines are yellow, with light brown transverse bands, stoutly subulate, flattened at the base, and hard. The barbed bristles are dark brown, upright, and more or less persistent. The short woolly hairs are gray, shorter than the barbed bristles, and persistent. The leaves are subulate, green, and early deciduous.

The cactus flower is radiate. The receptacle is obovate, sparsely bearing protruding areoles, and the areoles have short woolly hairs, barbed bristles, and subulate spines. The sepal-like perianth segments are broadly obovate to narrowly obovate, with the apex acute or rounded and bearing a small mucro. The petal-like perianth segments are obovate or spoon-shaped obovate, with the apex rounded, truncate, or slightly concave. The filaments are pale yellow. The berry is obovoid, concave at the top, more or less narrowed at the base into a stalk-like form, smooth and hairless on the surface, purple-red, and the areoles have short woolly hairs, barbed bristles, and subulate spines. The seeds are numerous, flat and round, and pale yellowish brown. The flowering period is from June to October.

Cactus likes strong light and tolerates heat, drought, and poor soil. It has strong vitality and is undemanding in care, making it very suitable for growing on family balconies. The optimum growth temperature is 20 to 30°C, and during the growing period there should be a day-night temperature difference, ideally 30 to 40°C during the day and 15 to 25°C at night. In spring and autumn, watering should follow the principle of “do not water until dry, and do not let it become too wet”.

Cactus is native to the east coast of Mexico, the southern and southeastern coastal areas of the United States, the West Indies, Bermuda, and northern South America. It has become naturalized in the Canary Islands, India, and eastern Australia. It was introduced into China in the late Ming Dynasty, is commonly cultivated in the southern coastal areas, and has escaped into the wild in Guangdong, southern Guangxi, and the coastal areas of Hainan.

In China, cactus was first recorded as a medicinal plant in the Qing Dynasty in Zhao Xuemin's Supplementary Compilation of the Compendium of Materia Medica. According to that book, cactus is bland in taste and cold in nature, and its functions are to move qi and invigorate blood, clear heat and remove toxin, reduce swelling and relieve pain, moisten the intestines and stop bleeding, strengthen the spleen and stop diarrhea, and calm the mind and promote urination. It can be taken internally or applied externally to treat many diseases. In the Qing Dynasty, Liu Shanshu's Convenient Formulas for Plants and Trees records that cactus is bitter and astringent and cold in nature, that it is not difficult to treat five types of hemorrhoids with bloody diarrhea, that white ringworm in children is rubbed with sesame oil, and that insect sores and scabies are washed to relieve them.

Cactus is high in potassium, low in sodium, and low in sugar, with a sugar content even lower than that of lettuce and cucumber. It has long been a traditional food in the Americas and is an indispensable specialty vegetable and fruit in people's daily lives. People wash and chop cactus and boil it in soup, or roast it over a stove, or use it as a pie filling, or directly pickle fresh cactus, and some also use cactus to make wine.