Sunday, July 13, 2008

Milkweed

What’s blooming in the area: Tea and miniature roses, Apache plume, tall yucca, cholla, Russian sage, trumpet creeper, honeysuckle, silver lace vine, purple phlox, bigleaf globemallow, white sweet clover, oxalis, wild licorice, velvetweed, white and yellow evening primroses, datura, bindweed, milkweed, buffalo gourd, purple coneflower, wild lettuce, local dandelion, Hopi tea, hairy golden aster, zinnia, garden sunflower; more smooth brome hay cut.

What’s blooming in my garden, looking north: Golden spur columbine, coral beardtongue, hartweig, butterfly weed, yellow flax, chocolate flower, fern-leaf yarrow, blanket flower, coreopsis, anthemis, black-eyed Susan, Mexican hat.

Looking east: Large-leaf soapwort, bouncing Bess, snow-in-summer, coral bells, ipomopsis, California poppy, tomatillo, hollyhock, winecup, sidalcea, rock rose, pink evening primrose; buds on sedum.

Looking south: Blaze, rugosa and rugosa hybrid roses, tamarix, Illinois bundle flower, sweet pea, daylily.

Looking west: Lilies, catmint, ladybells, perennial four o’clock, flax, speedwell, purple ice plant, white spurge, sea lavender, Shasta daisy; buds on caryopteris.

Bedding plants: Snapdragon, sweet alyssum, petunia, moss rose, pepper, Dahlberg daisy, French marigold, gazania.

Inside: Aptenia, bougainvillea.

Animal sightings: Hummingbirds, dragonfly, monarch butterfly, grasshoppers, ants, bees on white sweet clover down the road.

Weather: Rain Monday night penetrated 1/4" in overgrazed land; Tuesday rain seeped 1/2"; Wednesday more rain and ground was damp 1 5/8" down; high winds followed by more rain Friday night; Saturday morning ground was only wet to 3/8" and back to sand by late afternoon. 15:41 hours of daylight today.

Weekly update: I confess I never paid much attention to milkweed flowers. As a child I saw the opened seed pods and touched the large, lance-like, grey-green leaves with their fuzzy bellies and embossed webs of ribs.

When some sprouted in my drive in Oakland County, Michigan, I finally noticed the dingy pink flower heads, and promptly forgot them. I get reminded each year when I see Asclepias syriaca flowers on the familiar leafy stalks along the road near the village.

When I got my first nursery catalogs in Michigan in 1986, they were advertising butterfly weed for its bright orange color. They didn’t explicitly call it a milkweed, and I’m not sure I recognized it from its name, Asclepias tuberosa. I tried some, but don’t remember having any great results.

I bought more when I got here because the perennials were described as drought tolerant. Actually, they like water, some shade and slightly acid soil. The taproots were so difficult to establish that when two finally survived, one where I planted it and one in a ditch where another had either migrated or gone to seed, I no longer paid them much attention. The combs were simply blotches of orange in an impressionist bed of yellows.

It wasn’t until a few weeks ago that I actually looked at a flower. I was stopped by the road when I noticed something white at my feet. I broke off a stalk, took a picture, completed my errand, and got back to the safety of my car.

Later I took down my Peterson and counted what looked like pointed upright petals. They were tiny but arranged much like those models of molecules teachers use to teach children physics: a central ball surrounded by five satellites held together by thick bars. In fact what I was looking at was not the flower, but an elaborate anther structure composed of five sets of outer and inner flaps (horns and hoods) and the central stabile of sexual organs.

The usual flower, the petals and sepals, began a bit below a hairy waist and pointed downward. On the milkweed I found by the roadside the top corona was more obvious than the petals. On the plants in my garden, light orange petals peel down from darker upright outer husks of the corona that camouflage the insignificant center.

Neither have leaves I associate with milkweed, even if both point up. The garden plant has dark-green lancets with lighter yellowish veins. The roadside one had leaves as thin as pine needs in groups of three and so sparsely spaced then stalks could be taken for tumble mustard.

Monarch butterflies prefer other species, but will lay their eggs on almost any member of the milkweed family because their caterpillars live on the proteins and carbohydrates in the leaves while absorbing toxic cardenolides that deter their predators into adulthood. The same chemicals concentrated in tuberosa’s root explain why its commonly called pleurisy root.

Last week I finally went to look for a common milkweed growing in a running ditch in the village. The five petals were opened flat into a star, making a lattice of the ball’s surface, but there was nothing special about the centers. The flowers still weren’t noticeable, not even to monarchs who get their nectar elsewhere.

Notes:
Peterson Field Guide. Southwestern and Texas Wildflowers, 1984, by Theodore F. Niehaus with illustrations by Charles L. Ripper and Virginia Savage.

Photograph: Butterfly weed with erect corona and downswept petals, 06 July 2008.

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