Mason Heberling

  • Welcome
  • Research
  • Publications
  • Photos
  • Collected on this day!
  • Welcome
  • Research
  • Publications
  • Photos
  • Collected on this day!

Collected on this day...

a weekly blog featuring specimens in the Carnegie Museum's herbarium.
​
each specimen has an important scientific and cultural story to tell.

September 8, 1991: 26 years ago today

9/7/2017

Comments

 
Picture
​Collected on September 8, 1991, this specimen was found near Tarentum, PA by Walt Zanol.  If you had to pick the most aggressive invasive plant in the Pittsburgh area, knotweed would be among the top choices.  This particular specimen is Bohemian knotweed (Fallopia xbohemica), a hybrid between giant knotweed (Fallopia sachalinensis) and Japanese knotweed (Fallopia japonica).  Japanese knotweed was introduced from East Asia and Giant knotweed came from Sakhalin (Russia).  The hybrid likely originated when these two species “met” after they were introduced in Europe.  Both species and their hybrid can be found around Pittsburgh, often in enormous dense clusters along highways and waterways.  Take note on your drive to work or walk in the neighborhood – knotweeds are all around! 
 
Giant knotweed is distinguished by its large (usually much larger than your hand), heart-shaped leaves.  Japanese knotweed and the hybrid Bohemian knotweed are much more difficult to distinguish, with much variation in leaf shape.  In fact, the hybrid was only recognized in the early 1980s and was largely overlooked in the US until even more recently.  Some suggest it invades more aggressively than its parents. Most specimens in the Carnegie Museum of Natural History’s herbarium were originally identified as Japanese knotweed.  Last year, Allison Cusick, Research Associate in Botany at the museum, went through all 212 knotweed specimens and reidentified many as the hybrid.  In fact, only 3 of the specimens from Allegheny county were identified as Japanese knotweed!

For more info, see Zika & Jacobson (2003) Rhodora 105:143-152. https://www.jstor.org/stable/23313523?seq=1#page_scan_tab_contents
Picture
All three knotweeds collected a couple weeks ago at the same site near the Allegheny River and Barking Slopes Conservation Area, New Kensington/Plum, PA.  Left to right: Japanese knotweed (Fallopia japonica), Bohemian knotweed (Fallopia xbohemica), Giant knotweed (Fallopia sachalinensis).
Comments

    RSS Feed

      Suggest a specimen!

      Your birthday, favorite species, collected by your house, a particular collector, etc...?
      [object Object]
    Submit

    Archives

    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017

    Categories

    All
    Amaryllidaceae
    Anacardiaceae
    Apiaceae
    Apocynaceae
    Aquifoliaceae
    Araceae
    Araliaceae
    Asparagaceae
    Asteraceae
    Betulaceae
    Boraginaceae
    Brassicaceae
    Cactaceae
    Caricaceae
    Caryophyllaceae
    Celastraceae
    Convolvulaceae
    Cucurbitaceae
    Cupressaceae
    Dioscoreaceae
    Ericaceae
    Fabaceae
    Fagaceae
    Geraniaceae
    Hamamelidaceae
    Holiday Posts
    Introduced Species
    Lauraceae
    Lycopodiaceae
    Malvaceae
    Melanthiaceae
    Melastomataceae
    Oleaceae
    Oxalidaceae
    Papaveraceae
    Pinaceae
    Plants Of The Anthropocene
    Poaceae
    Poisonous
    Polemoniaceae
    Polygonaceae
    Primulaceae
    Pteridaceae
    Ranunculaceae
    Ranunuculaceae
    Recollected
    Recollection
    Rosaceae
    Rubiaceae
    Salicaceae
    Santalaceae
    Sapindaceae
    Scrophulariaceae
    Solanaceae
    Type Specimens
    Ulmaceae
    Undetermined
    Violaceae

© Mason Heberling 2018
✕