Violet (Viola odorata)

Eucalyptus, a traditional Aboriginal remedy, is a powerful antiseptic used all over the world for relieving coughs and colds, sore throats, and other infections. It is warming and stimulating, and for many people its scent conjures up days spent in bed during childhood with eucalyptus and other oils smothered on the chest. Eucalpytus is a common ingredient in many over-the-counter cold remedies.

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. Thriving in marshlands and along the edges of mangrove swamps in warmer temperate and tropical climates—especially southern Asia—it develops into dense mats on mudflats. This herb has been a cornerstone of Ayurvedic medicine for supporting cognitive function and treating various nervous system disorders, and it is increasingly recognized in Western herbalism for its brain-enhancing properties.

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. Its name comes from the Norse word 'dylla,' meaning 'to soothe,' reflecting its calming properties. Catnip has an excitatory effect on cats but a sedative effect on humans.

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. For at least 2,500 years, coltsfoot has been taken as a cough remedy and smoked to ease breathing. The Greek physician Dioscorides in the 1st century CE recommended it for dry coughs and 'for those who are unable to breathe except standing upright.'

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. Known since ancient times as a “cure-all” for respiratory ailments, it clears congested phlegm and supports recovery from infections. Hyssop also has antiseptic qualities beneficial for cuts, abrasions, and insect bites.

Linden comprises deciduous trees growing to a height of 100 feet with smooth gray bark, heart-shaped leaves, and clusters of pale yellow flowers with winglike bracts. Native to Europe, it is found in the wild but is also much planted in gardens and along roads. The flowers are collected in summer. Greek myth recounts how the nymph Philyra, devastated after being raped by the god Cronus in the guise of a horse and giving birth to the centaur Chiron, begged the gods not to leave her amongst mortals. The gods granted her wish by transforming her into a linden tree, forever linking this graceful species with transformation and divine mercy.

Lobelia is an annual herb growing to 20 inches with lance-shaped leaves and pale blue, pink-tinged flowers. A powerful antispasmodic used for respiratory and muscle disorders, it was a traditional Native American remedy for many conditions. It was used as a 'puke weed' to induce vomiting, as a remedy for worms and venereal disease, and as an expectorant. 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 was effective for chest ailments because its leaves were said to resemble lung tissue. This folk belief, while not scientifically founded, turned out to have merit—the herb is indeed valuable for respiratory conditions.