The protea family
Proteaceae is the most distinctive material a florist can put in a container and the most misunderstood. Protea, banksia and leucadendron look prehistoric because in a real sense they are: this family was already diversifying before the southern continents separated, and its distribution today is a map of a landmass that no longer exists.
about 80 genera
roughly 1,700 species
The southern hemisphere, above all South Africa and Australia
Everything in this guide that belongs to Proteaceae
Proteaceae grows in South Africa, Australia, South America and a scatter of Pacific islands, and almost nowhere else. That is not a coincidence of climate. Those landmasses were joined as Gondwana, and the family was established and spreading before they broke apart. The plants did not cross the ocean. The ocean opened underneath them.
The name comes from Proteus, the shape shifting sea god, and Linnaeus chose it because the forms vary so wildly. A banksia cone, a king protea the size of a dinner plate and a fine leaved leucadendron do not look like relatives until you take the heads apart.
When you do, the arrangement is consistent. What reads as a single flower is a dense head of many small ones packed together and surrounded by stiff colored bracts. The bracts do the advertising, and they are the part that lasts.
These plants evolved on some of the poorest soils on earth, particularly the ancient sandstone of the Cape and of western Australia, where phosphorus is close to absent. Their answer is proteoid roots, dense mats of fine rootlets that scavenge nutrients with remarkable efficiency.
That efficiency turns into a liability the moment conditions improve. Ordinary fertilizer will kill a protea, because the roots take up phosphorus so aggressively that normal garden levels poison the plant. Anybody selling these as garden stock needs to say so plainly, because the instinct to feed a struggling plant is exactly what finishes it.
Many members are also fire adapted. Banksia holds its seed in woody cones that stay sealed for years and open only when heated, dropping seed onto ground just cleared and fertilized by ash. The cones sold as dried decoration are those seed stores.
Vase life here is excellent, two to four weeks fresh and effectively unlimited once dried. There is one characteristic fault, and it is worth knowing because it looks like rot and is not.
Protea leaves blacken, usually starting at the tip and working back along the leaf while the flower head itself stays perfect. It happens when the leaves run short of sugars in low light and the plant begins breaking down its own tissue, and any interruption to water uptake makes it worse.
Keep them in good light rather than a dim corner, recut and change the water regularly, and use a flower food with sugar in it. If blackening starts anyway, stripping the affected leaves costs nothing: the head is the product and it will carry on for weeks without them.
The macadamia nut is in this family, which surprises almost everybody. It is the only significant food crop Australia has given the world and it grows on a tree closely related to the banksia.
Grevillea and waratah belong here too, both familiar to Australian gardeners, and the waratah is the state flower of New South Wales. The king protea is the national flower of South Africa, which makes this one of the few families supplying two national emblems.
For a florist the practical point is that nothing else looks like this. When a customer wants something that does not read as conventional, one protea or a few stems of banksia will do more than any amount of unusual color in familiar shapes, and it will still be standing long after the rest has been thrown away.