Calendula (Calendula officinalis)

Aloe vera (syn. A. barbadensis) is a succulent commonly grown as a potted plant, notable for its thick, fleshy leaves that contain two distinct medicinal components. Historically, the inner clear gel was used for skin conditions and to promote wound healing (NCCIH), while the bitter yellow sap from the leaf base, often called “bitter aloes,” is a strong laxative.

Psyllium, also known as flea seed due to its small brown appearance, is produced by several Plantago species. It has long been used as a laxative, and MedlinePlus lists it as a bulk-forming laxative used to treat constipation. The seeds and husks have a bland taste and develop a jellylike consistency when moistened due to their high mucilage content. The plants are extensively cultivated, especially in India, and propagated from seed in spring. Seeds are harvested when ripe in late summer and early autumn.

Chinese rhubarb (Rheum palmatum) is a thick-rhizomed perennial, growing up to 10 ft (3 m) tall, with large, palmate leaves and small flowers. It has been used in Chinese medicine for over 2,000 years.

Slippery elm (Ulmus rubra) is a large tree native to the eastern U.S. and Canada. The medicinal part is the inner bark, prized for its high mucilage content. When soaked in water, it turns “slippery”; this mucilage is traditionally used to soothe the throat and digestive tract, and MSK says slippery elm may help relieve minor cough or sore throat, but there is no evidence it can treat infections or other serious medical conditions.

Bacopa, also known as Water Hyssop or Brahmi, is a creeping succulent perennial that can grow to about 20 inches. It features spatula-shaped fleshy leaves and pale blue or white flowers on slender stalks. It thrives in marshlands and along the edges of mangrove swamps in warmer temperate and tropical climates, especially southern Asia, where it forms dense mats on mudflats.

Bitter melon is an annual climbing vine reaching about 6.5 feet, characterized by deeply lobed leaves, yellow flowers, and distinctive orange-yellow fruit. Native to southern Asia and now common throughout tropical regions worldwide, it is harvested year-round. Its edible fruit is used both as food and in medicine to treat diabetes in regions including Asia, East Africa and the Caribbean; MSK says data on whether it lowers blood sugar are limited.

Cat's claw is a climbing vine that can grow to 100 feet or more, with stems up to 8 inches in diameter, large glossy leaves, and sharp hooks resembling a cat's claws. Native to tropical rainforests in the central and eastern Andes, especially Peru, Ecuador, and Colombia, it has also been found in Guatemala, Costa Rica, and Panama. Indigenous people of the Amazon rainforest have used cat's claw for centuries to ward off disease, and NCCIH says it is promoted today for osteoarthritis, rheumatoid arthritis, cancer and viral infections. NCCIH says there is no conclusive evidence from studies in people to support cat's claw for any health purpose. By the early 1990s, over-collection from the wild threatened the species' survival; only sustainably sourced stem bark should be used, rather than root bark.

Cleavers is a straggling, square-stemmed annual growing to 4 feet with whorls of lance-shaped leaves, clusters of small white flowers, and small round green fruits covered with hooked prickles. The name refers to the plant's ability to cling (or cleave) to fur or clothing. Common throughout Europe and North America and found in many other temperate regions including Australia, it grows prolifically in gardens and along roadsides. The Greek physician Dioscorides in the 1st century CE noted that shepherds used the stems to make sieves for straining milk.