German Chamomile (Chamomilla recutita)

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.

Catnip is a downy, aromatic perennial growing to 3 feet with heart-shaped, gray-green leaves and whorls of white flowers marked with purple spots. Native to Europe and naturalized in North America, it grows in dry wayside places and mountainous regions up to altitudes of 5,000 feet. The plant is gathered when in flower during summer and autumn. Catnip has an excitatory effect on cats.

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.

Marshmallow (Althaea officinalis) is a downy perennial up to about 7 ft (2.2 m), with thick white roots, heart-shaped leaves, and pink flowers. It is known for its high mucilage content.

Peppermint (Mentha × piperita) is a fast-growing, square-stemmed herb (commonly about 32 in / 80 cm tall), with lanceolate, serrated leaves and purplish flowers. A natural hybrid of watermint and spearmint, peppermint is renowned for its cooling, aromatic flavor, and mint plants have been used for digestive disorders since ancient Greece, Rome and Egypt. NCCIH says a small amount of research suggests enteric-coated peppermint oil capsules may improve IBS symptoms in adults, but there is not enough evidence to know whether peppermint leaf helps any condition.

Common plantain (Plantago major) is a low-growing perennial reaching up to about 10 in (25 cm), forming a rosette of broad, ribbed leaves and spikes of tiny green flowers. Often regarded as a garden weed, plantain has leaves rich in iridoids, flavonoids, mucilage and tannins.

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.