Nettle (Urtica dioica)

Gravel root is an erect perennial growing to 5 feet with whorls of pointed oblong leaves and clusters of purple-pink florets. Native to eastern North America, the root is unearthed in autumn. The plant's alternative name, Joe Pye weed, honors a Native American named Joe Pye. The root was listed in the Pharmacopoeia of the United States from 1820 to 1842.

Andrographis, commonly known as Green Chiretta or King of Bitters, is an upright annual herb reaching approximately 3 feet in height. Native to India and cultivated throughout northern regions of India and China, this bitter medicinal plant has been valued in Ayurvedic and traditional Chinese medicine for centuries. MSK notes that it has been studied mostly for colds, flu and upper respiratory infections. The plant thrives on plains and in forest undergrowth, where its spotted pale brown or purple flowers and long seed capsules distinguish it from other medicinal herbs.

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.

Boneset (Eupatorium perfoliatum) is a bitter-tasting, upright perennial that can reach about 5 ft (1.5 m). It has lance-shaped leaves and clusters of small white or sometimes purple florets.

Burdock is a sturdy, bitter herb with large leaves.

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.

Codonopsis is a small twining perennial growing to 5 feet with oval leaves and pendulous green and purple bell-shaped flowers marked with purple in summer. Native to northeastern China and growing throughout the region, especially in the Shanxi and Szechuan provinces, it is propagated from seed in spring or autumn, and the root is harvested in autumn once the aerial parts have died down. Codonopsis holds a central place in Chinese herbal medicine.

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.