Pages

Wednesday, April 25, 2012

The Barberry Family (surprisingly endearing)


The name barberry congers up old-world images of hedgerows and folk tales.  I have never had much connection to the genus, mostly equating it with less-than-attractive, thorn-laden ornamentals that felt like just one more invader from California; a Mediterranean-climate import that made me protectively adore our native relative - Mahonia, or Oregon-grape. Tall or low ("dull" seems like such a demeaning name for such a sturdy little plant), Oregon-grape fills the temperate forests of Cascadia.  Their tough leaves last through the sodden winters with tenacity, and the yellow flowers brighten up the equally-soggy springs with a hardy cheer.  The flowers withstand a pelting from large spring raindrops, and when the sun breaks through, they heat up enough to release their sweet-smelling nectar.   These attributes make it an apt specimen for Oregon's state flower.

This perennial familiar, however, has some surprises of its own.  Mahonia (with a name that rolls so sweetly off the tongue) has long been the accepted genus for our local species.   It is now categorized as the genus Berberis - a name as prickly as the plants tend to be.  The entire barberry family, in fact, has surprises around every taxonomic corner - from common, herbaceous ground covers to unexpected ornamentals.

http://www.mobot.org/mobot/research/apweb/welcome.html

The Barberry family (Berberidaceae) spans across the temperate regions of North America, Europe and Asia, with some species occurring on the west cost of South America.  It isn't an especially large family; it is comprised of about 17 genera with 700+ species. They have a terminal inflorescence, most often in a raceme. Their flower parts are whorled and usually 3-merous (plant-speak for "in sets of 3").  The family has nectary glands present in the flowers, bringing in pollinators.  And the stamens of the plants react to those insects by springing into them.  They term the stamens as "irritable."  There is a great set of photos on this site at the University of Texas herbarium that shows images of the stamens reacting to stimulation by springing inward toward the pistil and then retracting.
Most plants in this family have an intense yellow tone to the inner bark, wood or roots.  This is from a compound called Berberine which has a vast amount of uses. Its strong color transfers well as dye for wool, cotton and wood.   It is a strong anti-microbial, and can be used to treat many infections.

Globally and locally, the family has some genera that may be of surprise.  In the northwest, the family contains three genera. Most commonly known is Oregon-grape (once Mahonia, now Berberis).  But there are two more that were a surprise to me: Vancouveria (inside-out flower or duck's foot) and Achlys (vanilla leaf).  Vancouveria is a total surprise; I can see the family resemblance if I squint my eyes and look sideways at it. Achlys starts making more sense when you see other members of the family outside of the northwest.  Jeffersonia is a two-leaved plant from the eastern US that looks much like Achlys. And Podophyllum (a.k.a. Sinopodophyllum or mayapple) shows a similar theme. 

Berberis aquifolium, tall Oregon-grape
Tall Oregon-grape, Berberis aquifolium

The Berberis near to my heart is the above-mentioned Oregon-grape.  Oregon-grape has three species in Oregon and Washington: tall (B. aquifolium), low (B. nervosa), and creeping (B. repens). They have evergreen, holly-like, compound leaves.  The plants can sometimes be difficult to tell apart.  There are general rules that are inevitably broken.  Creeping Oregon-grape tends to grow on the east side of the Cascades.  It's leaflets are dull below and pinnately veined.  Tall and low Oregon-grape grow on both sides of the Cascades.  Tall tends to grow in drier, sunnier locations or with well-drained soil.  They can grow quite tall - up to six or eight feet and have around 5 to 9 leaflets.  Low Oregon-grape stays relatively short - just around a foot, and have between 9 and 19 leaflets.  But landscapes with iterations of water, soil, and sunshine make plant taxonomy tricky.  The veination helps at times like these: low Oregon-grape has more palmately veined leaflets, while tall Oregon-grape's are distinctly pinnate



Berberis aquifolium, tall Oregon-grape
Tall Oregon-grape, Berberis aquifolium - flower

Berberis aquifolium, tall Oregon-grape
Tall Oregon-grape, Berberis aquifolium - flower dissected

As I returned home from collecting Oregon-grape flowers for dissecting, I was struck by how the Nandina (heavenly bamboo) next to my driveway had a similar affect to the Oregon-grape.  It has tall woody stems with compound leaves and racemose flowers.  Imagine my surprise when its genus was listed below the family! Below are some more images, genera and random tidbits of information that belong to the surprisingly-endearing Barberry family.
Mahonia oiwakensis
(M. lomarifolia)

- Interestingly, according to The Plant List not all of the Mahonia genus has been lumped into Berberis, as is the case with the plant to the left.  Considering the type species for the genus has been moved, will the rest of them be soon to follow?  Only the taxonomists behind the curtain can foretell.

- I especially enjoy this description of Oregon-grape from a National Geographic Magazine in 1917.

- Oregon-grape was introduced to Europe in the 1820s as an ornamental.  Many different hybrids were developed and within 40 years, it hopped out of cultivated gardens and subsequently became invasive. here's a source for more info

- The photograph to the left seems to be typical of any I can ever manage of M. oiwakensis.  It grows monstrously tall, and when it's towering over you, one can imagine what it felt like to be a prey animal in the Jurassic age. 
Epimedium acuminatum
- VancouveriaEpimendium, Jeffersonia and Plagiorhegma all have myrmecochorous features on their seeds.   This difficult-to-pronounce word simply means that their seeds are dispersed by ants.  But the relationship is anything but simple.    The plants have evolved a fleshy structure on their seed full of fats and proteins that acts as a trade-off for all of the ants' hard work.  They bring the seed back to their nest, remove the fats and discard the seed in middens.

- Epimedium has four nectar spurs coming from the four inner tepals, shown to be involved in nectar feeding by bees with long proboscises (I had to look up the plural of "proboscis"),  like the longhorn bee or bumblebees (Bombus diversus).

- In a fabulous study by Janene Auger, M. repens seeds that were ingested by black bears had a significantly higher germination rate than the controls.  Imagine that summer internship -  collecting and processing bear scat.
    Dysosma versipellis
Berberis maderensis

 
Epimedium (perralchium?)


Sunday, February 12, 2012

Drosophila suzukii

I am into my third week with Oregon State University extension and I have broadened my scope of knowledge in two directions I never could have predicted.  The direct object... blueberries. The subject... an invader: only millimeters in size, he boldly wears his identification on his sleeve (well, wing) while she takes refuge in the disguise of similar, but innocuous species, until you see her ovipositor that is: a specialized organ used for egg laying, hers has a hardened and serrated edge that she uses to ruthlessly cut open the sweet, fresh skin of our most beloved of fruits. That's right... it's the dreaded Drosophila suzukii or spotted-wing Drosophila.
Little is known about this infamous creature.  She has traveled the globe looking for her next victim. Native to southeast Asia, they have only been in Oregon since 2008. Unlike most vinegar flies (fruit flies as we laymen like to call them) D. suzukii prefers to lay her eggs in fruit that is just becoming ripe.  The larvae then destroy the fresh fruit, damaging the commercial value.  Each female can lay up to 350 eggs in her short (30 day) life.  With around six generations within a year, each generation increases the population exponentially.  It could become a major pest to northwest growers as it attacks many kinds of fruit: blueberries, cherries, strawberries, peaches, and more.  For blueberry growers, this is the first major pest, and historically they have needed few, if no, pesticides.
The goal of research now is to fully understand the life cycle and control of the flies in this climate.  Where do they overwinter and on what do they feed? What will the best baits be for catching them and monitoring population size? Could we find an attractant/pesticide combo that diminishes the population early in the growing season thereby making the rest of the year manageable? With these important questions, I began my work.
First, we had to go find ourselves some flies.


Off to a local blueberry grower that is a partner for the OSU research.  We set up some traps with various baits. The traps are intended to be easy and cheap for a grower to make themselves.  They are red, Solo party cups, holes drilled in the side with a lid on top to keep out irrigation and dew and filled with a concoction of temptations like banana or apple-cider vinegar. We wait a week and have more flies, even at the end of January, than we could easily count.
Next to the identification:
Male spotted-wing Drosophila are easy.  That's right... they have a spot on their wing.
male D. suzukii
As stated earlier, female spotted-wing Drosophila look a lot like other vinegar flies... red eyes, auburn thorax and banded abdomen.
female D. suzukii

until you pop out her ovipositor.


female ovipositor
The ovipositor of the female spotted-wing Drosophila is unique. Hers is a sclerotized (hardened) ovipositor with serrated edges used to slice open the skin of ripe fruit.
Becoming familiar with spotted-wing Drosophila means being able to distinguish it from similar flies.
One of these flies is not like the other...
With time, the color of her thorax looks slightly off the color of other Drosophila, the bands of her abdomen aren't quite as clear as the others' bands, and the unaided eye starts being able to pick them out with reasonable accuracy that is easily checked under the microscope.
Here lies the foundation for the coming months; hundreds (sometimes thousands) of flies to count in a week, subsampling methods to design and test, numbers to crunch, theories to formulate and test.  It is the scientific process from inception to resolution.  With any luck, it will lead to increased understanding of the flies, more fresh fruit with fewer pesticides.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.