Eucalyptus (Eucalyptus globulus)

American spikenard (Aralia racemosa) is a tall, aromatic perennial bush up to about 6½ ft (2 m), with fleshy roots, large compound leaves, and clusters of greenish-white flowers followed by red or purple berries.

Sweet violet is a creeping perennial growing to 6 inches tall with toothed oval leaves and attractive violet-blue or white flowers with a five-petaled corolla. Native to much of Europe and Asia, it is a common wayside plant also found along roadsides and in woodlands. In classical mythology, sweet violet was associated with death.

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.

Coltsfoot is a perennial herb growing to 12 inches with flowering stems covered in purple scales, yellow-gold flowers, and heart-shaped leaves. Indigenous to Europe and northern Asia and naturalized in North America, it is commonly found along roadsides, on verges, and in open areas. The flowers are gathered in late winter, and the leaves in summer.

Garlic (Allium sativum) is a bulbous perennial in the onion family, recognized for its sharp flavor and characteristic odor. It is widely used in cooking, and crushed fresh garlic contains allicin. NCCIH says garlic supplements may lower cholesterol, blood pressure and blood sugar to a small extent, but very little research has tested claims that they boost immunity.

Hyssop (Hyssopus officinalis) is a semi-evergreen shrub growing up to about 2 ft (60 cm), with narrow leaves and clusters of bright blue, two-lipped flowers.

Lobelia is an annual herb growing to 20 inches with lance-shaped leaves and pale blue, pink-tinged flowers. It was used as a 'puke weed' to induce vomiting. Lobelia was also smoked as a substitute for tobacco and was reputed to share some of its magical qualities. Indigenous to North America, especially eastern parts of the United States, it grows by roadsides and in neglected areas, preferring acid soil. The aerial parts are harvested in early autumn when the seed capsules are most numerous and are carefully dried. Its use was later championed by the American herbalist Samuel Thomson (1769-1843), who made the herb the mainstay of his therapeutic system, mainly using it to induce vomiting.

Lungwort is a perennial herb growing to 1 foot with broad oval basal leaves, smaller upper leaves mottled with white spots, and clusters of pink-purple flowers. Native to Europe and the Caucasus, it flourishes in mountain pastures and damp sites. The leaves are gathered in late spring. According to the medieval Doctrine of Signatures, which held that a plant's appearance pointed to the ailment it treated, lungwort got its name because its leaves were said to resemble lung tissue. This folk belief is not scientifically founded.