★★★★★
Manuka (or Red Tea Tree) is the smaller tree/shrub/bush and Kanuka (or White Tea Tree) is the much taller, tree version. The early European adventurer and sea captain, Captain James Cook pioneered the protective measures taken to prevent Scurvy (lack of Vitamin C) on the ship "Endeavour", partly by giving his crew lemon juice etc. However, when he reached New Zealand he brewed a "tea" using "Tea" tree or Manuka leaves (hence the name). He also brewed beer with it, which was nutritious as well as making you smile.
In addition, we still have Scurvy grass near some of our beaches which he forcibly fed to his crew, which also helped them resist scurvy on long voyages. You do NOT want to get scurvy!! One French voyager was loosing one man every day when he visited New Zealand in 1769 because he did not know this medical fact! His men must have died horribly.