Couch Grass (Elymus repens)

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.

Goldenrod is a perennial plant growing to 28 inches with toothed leaves and branched spikes of golden-yellow flowers. Native to Europe and Asia and naturalized in North America, it prefers open areas and hillsides and is gathered in summer while in flower. The herbalist John Gerard commented wryly in 1597 about how goldenrod's value plummeted once it was discovered growing locally in Hampstead wood, London, noting society's tendency to esteem things only while they remain rare and foreign. Four hundred years later, this observation still rings true.

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.

Pau d'arco is an evergreen tree that can reach 100 feet in height, producing pink flowers. The bark of this South American tree is used as a tea in traditional medicine for a wide range of ailments; MSK says its antibacterial and anticancer effects in laboratory studies have not been shown in humans. The tree grows in both mountainous terrains high in the Andes and in low-lying areas of Paraguay and Brazil. The prized inner bark is collected from wild-growing trees throughout the year.

Buchu is a strongly aromatic, bushy shrub reaching about 6½ ft (2 m), with slightly leathery, dotted leaves that release a distinctive scent.

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.

Uva-ursi is a low-lying evergreen shrub growing to 20 inches tall with long trailing stems, dark green leaves that are glossy on the upper side, bell-shaped pink flowers, and small glossy red berries. The name means 'bear's grape' in Latin, as bears are fond of the fruit. Native to Europe and naturalized throughout the northern hemisphere up to the Arctic, it grows in damp undergrowth, heathland, and grassland conditions. The plant was first documented in The Physicians of Myddfai, a 13th-century Welsh herbal text.

Agrimony is an erect, slightly aromatic perennial that grows to around 3 ft (1 m). It has paired leaves that are green above and silvery-green beneath, and it bears small, bright yellow, five-petaled flowers arranged on slender spikes.