Thursday, July 16, 2009

Hemerocallis 'Memories of Oz' (top) and 'Skinwalker' Daylily selections in quarantine...curious flowers!

After it has been determined that they aren't carrying Daylily Rust, they'll go out into the Daylily beds in the Boxwood Collection. The Daylily collection, though perhaps a bit past peak, is still beautiful and worth a visit. It's integrated into the Boxwoods inside the Bladensburg Road fence.

If there are too many Daylily cultivars, at least they don't all look the same. Hey, there are three basic colors for Peonies and what, half a dozen? flower forms. Where do the hundreds and hundreds of cultivars come from? And don't get me started on Iris or Hostas. Daylilies come in a lot of colors in lots of shades, with lots of differently shaped flowers in different sizes that bloom from early summer to late fall. Often they have interesting names; if 'Skinwalker' is a bit gruesome, it's at least colorful and evocative?

Daylily Rust is a disease caused by a, go figure, rust fungus, Puccinia hemerocallis. I remember a related fungus, Puccina graminis, from pathology classes in college. All rusts are pretty similar. Their lifecycles are curious in that, though they do most of their damage on a particular plant species, they normally require a separate host to complete the sexual portion of their life cycles. The primary alternate host of our rust is plants of the genus Patrinia. The fungus is Asian, and so far as I know Patrinia is Asian. I know I never liked Patrinia scabiosafolia, a tall yellow flowered late-summer bloomer. It's pretty enough but has an unpleasant odor. I remember it growing in the "Korean Triangle" (that is now Asian Collections bed KO). Daylily Rust, however, doesn't need an alternate host; the spores it produces on one Daylily are able to infect another. I have a vivid recollection of Andre Viette declaiming vehemently against the evergreen daylilies, claiming that they were a large part of the reason for the diseases spread. And maybe they are.

No comments: