Chinese Rhubarb (Rheum palmatum)

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

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.

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.

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.

Black pepper is a perennial woody climbing vine growing to about 16 feet, with large oval leaves, spikes of small white flowers, and clusters of small round fruits that ripen from green to red. Native to southwestern India and now cultivated in tropical areas worldwide, the fruit is harvested from plants that are at least three years old. Different processing methods yield green, black, red, and white peppercorns, each with distinct flavors and uses. Cultivated as both a spice and medicine since ancient times, pepper was such a prized commodity in world trade that Attila the Hun reportedly demanded 3,000 pounds of it as ransom during his siege of Rome in 408 CE.

Boldo is a strongly aromatic multi-branched evergreen shrub or tree growing to 20 feet. It has egg-shaped leathery leaves with a lemony scent, clusters of white or yellow bell-shaped flowers, and small yellow berries. Native to Chile and Peru, it has become naturalized in the Mediterranean region and the West Coast of North America, where it grows on dry sunny slopes and in mountain pastures in the Andes. It is widely cultivated, and its leaves are gathered throughout the year.

Caraway is an aromatic annual herb growing to 2 feet with a ridged stem, feathery leaves, and umbels of white flowers in midsummer. Exploding capsules release two small narrow seeds. It grows wild in Europe, North Africa, and Asia, preferring sunny sites up to 6,600 feet above sea level. Cultivated in Europe, Russia, North Africa, and the United States, the seeds are harvested ripe in late summer. The seeds are commonly used in cooking.