Deadly Nightshade (Atropa belladonna)

Angelica (Angelica archangelica) is a large, aromatic biennial herb growing up to about 6½ ft (2 m), with ridged hollow stems, bright green divided leaves, and greenish-white flowers arranged in umbrella-like clusters (umbels).

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.

Calendula (Calendula officinalis) has bright orange daisy-like flowers.

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.

Corydalis is a small herbaceous perennial growing to 8 inches with narrow leaves and pink flowers. Native to Siberia, northern China, and Japan, it is commonly cultivated in eastern and northeastern parts of China. Propagated from seed in early spring or autumn, the rhizome is harvested in late spring and early summer when the aerial parts have withered. It has been part of Chinese herbal medicine since at least the 8th century.

Couch grass is a vigorous perennial growing to 32 inches with a long, creeping rhizome, slender leaves, and erect spikes bearing green flowers aligned in two rows. Found in Europe, the Americas, northern Asia, and Australia, it is an invasive weed harvested throughout the year. In times of famine, the root was roasted and ground as a substitute for coffee and flour.

Fenugreek is much used in herbal medicine in North Africa, the Middle East, and India. Its seeds have been used to increase breast-milk production; NCCIH says studies of this use have had mixed results. Fenugreek is also thought to be antidiabetic, although NCCIH says there is not enough high-quality evidence to know whether it helps diabetes.