Friday, December 6, 2013
Every now and then, someone will try to play “stump the Botanist,” and bring us a really weird plant or plant part as a challenge. It can be tough, but we always get it, eventually. (I know I am setting myself up for it now!) And sure enough, not too long ago, one of my former advisees brought this thing in to see if he could rattle his old professor. It almost worked. I first thought it was the fruiting structure of some unusual species of Magnolia, but something about it just wasn’t right...This is a plant that you won’t see growing in the wild unless you are in Australia. It’s a member of the rather unusual family Proteaceae, one which consists mostly of woody plants, and is distributed mostly in the southern hemisphere. Many of the genera making up the Proteaceae are centered in Australia and southern Africa. The genus in which our Mystery Plant is placed is a rather flamboyant one, with very attractive flowers. The flowers are small and colorful, and they tend to be tightly packed together into compact spikes. These flowers also produce large amounts of nectar, and as you might expect, are thus important as food sources for a variety of animal species, including various birds and bats.
It was the father of Plant Taxonomy, Carl Linnaeus, who named this plant genus in honor of Joseph Banks. Banks is remembered for quite a number of botanical adventures, including his famous voyage with Captain Cook to the South Pacific. His priceless collection of plant specimens remains at the Natural History Museum in London, on Cromwell Road, if you ever want to visit: http://www.nhm.ac.uk/
The mysterious thing on my desk? It is indeed a woody, fruiting structure of this Australian plant. It came actually from a dried arrangement, and I think you can easily see how such an odd looking thing might be prized for making fancy floral displays. You’ll note that the old flowers were tightly spiraled around a central axis, upon which are the remains of scattered fruits. (It turns out that usually only a few flowers actually will set seed.) The fruits themselves are dry at maturity, and they split --horizontally-- along one line, so we can call each one a follicle. (Flash back to the fruiting structure of a Magnolia once again: its fruits, too, are follicles, tightly spiraled on the axis. But in Magnolia, the individual follicles split vertically. And besides, a single Magnolia cone comes from a single flower. Our Mystery Plant’s cone represents a lot of individual flowers stuck together on the same axis.)
Actually, the use of the word “cone” is a problem here. Botanically, cones are only produced by conifers, such as the familiar pines and firs, which don’t produce any flowers at all. (But for convenience, I think it’s OK to refer to the fruiting structure of a Magnolia, or of our Mystery Plant, as a “cone.”)
[Answer: “Firewood banksia,” Banksia menziesii]
John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences, Columbia SC 29208. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or call 803-777-8196, or email firstname.lastname@example.org.