Friday, August 31, 2012

Orange Coneflower

One plant that doesn’t seem much bothered by the drought is Orange Coneflower, Rudbeckia fulgida.  It may appear to be a bit worn, but that’s its normal condition at this stage.

The fertile flowers are found in the central disk.  The flowers mature in succession, beginning with the outer edge and moving toward the center of the disk.  As blooming progresses, the disk expands upward until the center sits well above the yellow rays.

Orange Coneflowers tend to grow in wetter conditions such as are found at the base of slopes or in natural drains through the field.  They also tolerate dry conditions.  I think these two characteristics account for the plant’s vigor during this year’s unusual weather conditions.

Orange Coneflowers are hardy perennials.  Flower stalks will die over winter.  Next year’s growth will come from basal rosettes that form from short stolons produced by the flowering plant.  These basal rosettes typically remain green through the winter and will develop rapidly as soon as it warms in the spring.

Several insect species find the Orange Coneflower of interest.  An unidentified moth larva boring up the center of the stalk produces this dusty material.  The timing of this activity doesn’t seem to affect the ability of the plant to complete flowering and produce viable seed.  Over half of the plants typically contain one or more larvae.

Small bees are the most numerous of the flower visitors.

A few Soldier Beetles are around, but I’m seeing fewer than normal for this time of year.

This neat little fly spent quite some time moving from flower to flower.  This is a member of the Tachinid Fly family, the larvae of which develop inside an insect host that ultimately does not survive the encounter.  Most in that family are big, hairy brutes.  This fellow is a species of Cylindromyia, a genus of wasp mimics.  I don’t see these guys very often and enjoyed observing this one for the few minutes it was around.

There appears to be some type of larva feeding down among the disk flowers and leaving a mass of excrement to mask its passage.  I dug into several of the affected flowers and found nothing but an empty tunnel.  One thing noticeably absent from the flower heads was Crab Spiders.  I can usually find dozens of these small yellow spiders perched on the flowers.  Here is one more regularly common animal species that has failed to appear this year.


  1. These look more yellow than orange. Beautiful though. I just photographed this summer many varieties over at the Göteborg Botanical Gardens as they had a Desert Theme this summer.

    I also love Mexican Hat which has some similar characteristics. Love the pics of various insects as well.


  2. Thanks Kevin. I bet the desert plants were really interesting. I have a fascination for plants that survive such a dry environment.