EPOW - Ecology Picture of the Week

Larkspur Stories

Upland Larkspur (Delphinium nuttallianum), Family Ranunculaceae
Mosier, Oregon USA

Explanation:  This striking wildflower is relatively common in woodlands through western North America.  But look close; it has some interesting stories to tell.

Like many other native wildflowers, upland larkspur produces nectar that attracts pollinating insects.  But did you know that nectar often contains microorganisms such as yeast, that function to determine the sugar content?  And that pollinators serve to transfer (are vectors of) yeast, inoculating from plant to plant (Schaeffer et al. 2015).

Moreover, maintaining the diversity of pollinators associated with upland larkspur seems to depend on maintaining the variation in the occurrence and density of the plant itself over space and time (Schaeffer et al. 2015). 

Upland larkspurs are native to the inland sagebrush steppe region, but also occur in a wide variety of other woodland and open environments.  I photographed the specimen in this week's presentation along the Columbia River Gorge in Oregon, on the spine between west and east Cascades.  

As beautiful as this plant is, it is also poisonous to livestock, and has been a bane of ranchers.  Upland larkspurs, along with a number of other herbaceous plant such as locoweed, lupine, death camas, snakeweed, threadleaf groundsel, milkvetch, and others, increased in density when rangelands became heavily grazed (Ralphs 2002).  Under better management, though, such plant species have declined but still remain troublesome in some areas.  And the plants seem to be more toxic in their vegetative growth stage than in the reproductive, blooming phase (Majak 1993).
  

Information:
   Majak, W.  1993.  Alkaloid levels in a species of low larkspur and their stability in rumen fluid.  Journal of Range Management 46(2):100-103.
   Ralphs, MH.  2002.  Ecological relationships between poisonous plants and rangeland condition: a review.  Journal of Rangeland Management 55(3):285-290.
   Schaeffer, RN, RL Vannette, and RE Irwin.  2015.  Nectar yeasts in Delphinium nuttallianum (Ranunculaceae) and their effects on nectar quality.  Fungal Ecology 18:100-106.