Spikenard (Aralia racemosa)

For many people the scent of eucalyptus conjures up days spent in bed during childhood with eucalyptus and other oils smothered on the chest. Eucalyptus is a common ingredient in many over-the-counter cold remedies.

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.

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.

Blue cohosh is an upright perennial herb reaching 3 feet in height, with large three-lobed leaves, yellow to purple flowers, and striking blue berries. It grows wild in much of eastern North America from Manitoba to Alabama, preferring woodland valleys and damp, north-facing slopes. The name 'cohosh' comes from the Algonquin language, and the plant was a popular remedy among many Native American tribes.

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.

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.

Biennial herb growing to 8 in (20 cm). Has red blotches on stem, crinkled lance-shaped leaves, 4-petaled yellow flowers, and elongated seed capsules.