The tea family
Theaceae is a small family of glossy leaved shrubs and trees that produced the second most consumed drink on the planet, an important cooking oil, and a tree that has not been seen growing wild since 1803 and survives only because somebody collected the seed.
around eight genera
roughly 250 species
Eastern and southeastern Asia, with a few in the Americas
Everything in this guide that belongs to Theaceae
Green tea, black tea, white tea, oolong and pu-erh are not different plants, different species or different varieties in any meaningful sense. They are all leaves from the same shrub, and the differences between them are entirely a matter of what was done to the leaf after it was picked.
The variable is oxidation. Torn or bruised tea leaf begins to oxidize immediately, the way a cut apple browns, and every style is a decision about when to stop that. Heat it almost at once, by steaming or pan firing, and the enzymes are killed and the leaf stays green. Let it run to completion and it goes fully dark, which is black tea. Stop it partway and you have oolong, which is not a halfway house so much as an entire craft of its own. White tea is young buds barely handled at all. Pu-erh goes the other way and is aged with microbes over years.
One shrub, five drinks, and the whole difference is timing and handling.
In 1765 John Bartram and his son William found a small tree with white camellia like flowers growing along a river in Georgia, in one stand of a few acres and nowhere else on earth. They came back for seed. The last confirmed sighting of the plant growing wild was in 1803.
Nobody knows why it went. A root disease carried in with cotton is the usual suspect, and the population was tiny and confined to begin with. What is certain is that every single one of these trees now alive, in botanic gardens and private gardens all over the temperate world, is descended from the seed the Bartrams carried back to Philadelphia. They named it after their friend Benjamin Franklin.
It is one of the very few plants that is extinct in the wild and entirely secure in cultivation, and it was saved by accident by two collectors who simply liked the look of it.
Away from the drink, this family's other crop is oil. Seed from one camellia species is pressed for a pale cooking oil used across southern China at a scale most people outside it have never heard of, and it stands up to high heat unusually well. Another species gives the oil traditionally used in Japan on hair, skin and to protect steel blades from rust.
The genus name is a small injustice. It honors Georg Kamel, a Jesuit lay brother who ran a pharmacy in the Philippines in the seventeenth century and wrote carefully about the plants of the islands. He never worked on these plants and, as far as anyone can establish, never saw one. Linnaeus named the genus after him anyway as a compliment to his work, which is how a Moravian pharmacist ended up attached to the most famous flowering shrub in Asia.
The order this family sits in is one of the odder collections in botany. Alongside the tea family it holds the heathers and blueberries, the primroses, the Brazil nut, the kiwifruit, the persimmon and the sapodilla that chewing gum was originally made from. There is no visual thread running through that list at all, which is a useful reminder of how little classification has to do with resemblance.
Within the family, the genus worth knowing after the camellias is Stewartia, grown less for its flowers than for its trunk, which sheds bark in plates and leaves a smooth polished surface mottled in cinnamon, gray and cream. In a winter garden it does more work than most things in flower.