Urban Gardener

Here’s a thing I never knew: Orchids are actually related to asparagus … and to hyacinths, irises and onions, among an absolute ton of other flowering plants. Actually, it even surprised the taxonomists (the people who make a living assigning plants to various families and changing their botanic names every time you think you finally have them right).

Until recently, taxonomists classified plants and animals by how they looked or how they were put together. Since orchids are so various and so weird, it was really hard for the scientists to classify them and to figure out when orchids emerged in flower history. The sheer number of flowers and reproductive parts made them difficult to trace. Even their pollen is confusing. There are tons of pollen samples in the fossil record. Paleobotanists use them all the time to figure out who was eating what in ancient times and which plants came before which others. Orchid pollen doesn’t appear among the fossils. It’s too delicate.

Now, of course, we can test the DNA of any living thing (not just suspected crooks). So naturally, the taxonomists started testing plant DNA. When they came to orchids, they discovered they were members of the Asparagales, a group that has just recently been taken out of the lily family and given its own status. These guys are distinguished not only by their DNA, but by the fact that they have a papery, "sooty" layer around their seeds.

Everyone had been so enthralled by the oddities of orchid flowers that they sort of ignored the fact that their seeds were a lot like asparagus (way smaller, of course). It took DNA testing to open their eyes.

You’d think the botanical types looking at all the various kinds of orchids, all of their shapes, all of their reproductive strategies and all of the places where they can be found would have figured that these were pretty ancient plants. After all, it does take a while for living things to change and diversify.

But everyone thought orchids were a relatively recent development. That is, until they looked at their DNA. Now they think orchids may have arisen as long as 90 million years ago — before palm trees, even.

Anyway, gossip that I am, I just had to share this stuff with you.

There will be a City Gardens contest this year. So now is the time to think about signing up; the entry deadline is June 10. Whatever you grow and wherever you grow it, there is a category for your efforts. For more information and an entry form, call 215-988-8897 or e-mail specialevents@pennhort.org. As usual, the contest is sponsored by the Pennsylvania Horticultural Society and the Penn State Urban Gardening Program.