A Multitude of Milkweeds

For some reason, I'm enamored with milkweeds. It probably started with their cachet as food for the caterpillars of monarch butterflies. All schoolkids learn about monarchs, I think, and most learn to love them. I know I did.

Then I discovered that milkweeds host an entire community of milkweed-specific insects, adapted to eat their poisonous tissues. Because these insects feed on milkweeds, they taste terrible and may even be poisonous in their own right. This means that few animals want to eat them. Not surprisingly, the milkweed eaters boldly advertise their untasty status with bright colors.

The final building block in my love affair with milkweeds was discovering how many of them have extremely fragrant flowers. I'm talking the kind of fragrance you drink in from several feet away, wondering, "What's that lovely smell?" Add in cool seed pods, pretty blooms in many species, and what's not to love?

So it's been fun to discover that we have several species of milkweeds on our property.

The first milkweed species we found was green antelopehorn, Asclepias viridis. Its flowers are neither showy nor fragrant, but the plants possess a certain quiet appeal nonetheless. They increase in overgrazed pastures. We have a lot of them.

Next I realized that we had a plant or two of common milkweed, Asclepias syriaca. Ironically, I've discovered that this species is the least common of the milkweeds that occur on our 10 acres. One of the taller, upright milkweeds, common milkweed has large, pretty pink pom-poms of fragrant flowers. Personally I think it would be a lot more popular with a less "common" common name.

I identified both of these 2 species shortly after we moved in. The third species was visible last year, but I didn't look at it closely enough to realize that it was different from the common milkweed. It's growing on the west banks of the draw in a small, loose colony of about 20 individual plants. (At least I think they're individuals. I haven't uprooted any to see if they are connected by underground rhizomes.) Another upright, pink, fragrant bloomer, it's known as showy milkweed, Asclepias speciosa. Its blooms are composed of fewer flowers than those of common milkweed, and they look "spikier". The leaves also tend to be held a little more upright than those of common milkweed.

About 20 feet away from the showy milkweed colony, back up on flatter land, I noticed a group of upright milkweeds this spring that didn't bloom as soon as the nearby showy milkweed or the further away common milkweed. Sure enough, when they did bloom they were a 4th species called smooth or Sullivan's milkweed, Asclepias sullivantii. Again they are pink and fragrant, but their odor is different, reminding me of cloves. Note that their flowers are not as "spiky" as the showy milkweed's, and their stem is smooth.

Backing up a bit, a month or so ago as the green antelopehorn was starting to bloom, I noticed a few scattered, smaller individual stems of what looked like milkweed, but it wasn't blooming. I marked several of them with orange flags and I've been monitoring them to see what they are. About 2 weeks ago, they started to bloom with odd little clumps of greenish-white flowers. Shown here to the right, the flower is on the lower left, the buds are on the right. I'd never noticed any milkweeds like these before but, in looking them up, I've learned that they are called green milkweed, Asclepias viridiflora. Chalk up another species that "magically appeared" after burning.

Finally, when I was out trying to get a decent photograph of the green milkweed, I noticed a singleton plant with much finer leaves and slightly different flowers. The flowers were still greenish-white, but they weren't as pendulous as those of the green milkweed. The overall effect of the plant was daintier, if taller. This turned out to be narrow-leaved milkweed, Asclepias stenophylla. As closeups of its flowers show, it's probably the least showy of them all (although the green milkweed is a close second), but I'm still glad to find it on our prairie.

I'm still waiting for the prom queen of the milkweeds, the orange-flowered butterfly milkweed or Asclepias tuberosa, to show up, but so far I haven't seen any sign of it. No luck finding swamp milkweed, Asclepias incarnata, or the endangered Mead's milkweed, Asclepias meadii, either. (Not that I think there's the slightest chance of finding the latter on this property, but one can always dream!!!) There are a few other species that are possibilities, but meanwhile I'm enjoying my embarrassment of milkweed riches with the 6 species I have found.