Tuesday, March 22, 2011

Is it chokeberry or chokecherry?

      Black chokeberry is one of the common names for Aronia melanocarpa.  The name “chokeberry” can easily be misunderstood or misread as the word “chokecherry.”  Chokecherry is the common name for a different plant --  .  In fact, the two plants are only distantly related within the Rosaceae or rose family of plants.  These two species have some similarities but many differences.  For example, chokecherry has toxicity issues but chokeberry does not. 




      The leaves and seeds of Prunus virginiana contain varying amounts of hydrocyanic acid (prussic acid) which ionizes in water and give off cyanide which is highly toxic.  Ingestion of about 0.25 percent of an animal’s weight in leaves can be fatal to livestock.  Poisoning occurs when susceptible animals consume a relatively large amount of leaves over a short period of time.  Chokecherry is toxic to horses and animals with segmented stomachs (rumens).  Ruminate animals include domestic cattle, goats, sheep, bison, buffaloes, camels, llamas, giraffes, deer, pronghorns, antelopes, and moose.  

     Chokecherry leaves are especially toxic after they have wilted, such as after a frost or after branches have been broken. Wilting causes the  hydrocyanic acid to be converted to cyanogenic glycoside, which makes the leaves sweet. Chewing the leaves can result in conversion to cyanide due to the presence of digestive enzymes in the mouth.  Chokecherry seeds are also toxic.  Although uncommon  there are recorded incidences of children who got sick and died after eating relatively large quantities of chokecherry seeds. 

      Currently, there is no data in the scientific literature about any unwanted or toxic effects of Aronia melanocarpa fruit, seeds, or juice or extracts made from the aronia berries.  The leaves, stems, and roots have not been investigated as extensively as the fruit.  However, there is no information or reports of toxicity of any parts of Aronia melanocarpa or any of the aronia cultivars.

Chokecherry Fruit

      Further adding to the confusion between black chokeberry and black chokecherry is the existence of Prunus virginianaMelanocarpa’ or Prunus virginiana var. melanocarpa.  This cultivar or variety name is the same as the specific epithet or the last part of the scientific name of chokeberry -- Aronia melanocarpa.  To avoid confusion, it is preferable to use the genus name of Aronia melanocarpa as its common name -- aronia.
   
     The genus name of many plants is used as their common name.  For example, hosta is the common name of a very commonly grown herbaceous perennial plant grown in many landscape plantings.  The genus name for hosta is HostaIn the past, hosta plants were also sometimes called plantain lily and funkia.

Hosta

      Getting back to the differences between chokeberry and chokecherry, there are several easy ways to tell them apart.  Their fruit looks similar but is easy to identify by the size and number of seeds.

      Chokeberry (Aronia) fruit has five or less seeds per fruit.  The seeds are small and barely noticeable when you eat the fruit, like the seeds in blueberries or strawberries (see photos below).


      Chokecherry (Prunus) fruit has a single seed known as a stone or pit.  This type of fruit is commonly known a stone fruit but the botanical name for this type of fruit is a drupe.  A drupe consists of a relatively thin outer epicarp (skin), a relatively thick, fleshy or fibrous mesocarp (flesh or meat), and one large pit or stone (seed) enclosed by a hardened endocarp (seed coat).

     The genus Prunus includes peach, nectarine (fuzz-less peach), almond, plum, cherry, olive, elderberry, coconut, and jujube.  Almonds are like peaches but they have an edible seed and their outer flesh is thin and not edible.


      Chokeberry flowers clusters are flat-topped but chokecherry flower clusters are long and more cylindrical.  The fruit of each is arranged in the same type of clusters as the flowers (see photos below).


      Chokecherry is native to almost all of North America except the extreme south east.  Chokeberry is only native to the northeastern quarter of the United States and adjacent areas of southeast Canada.

      The genus Aronia has been included in the genus Photinia in some classifications (Robertson, etal. 1991).  However, molecular data has confirmed that these genera are not closely related (Campbell, etal. 2007).  Ten years ago, one of the most popular shrubs in the South was the red-tip photinia (Photinia fraseri).  Everybody wanted this handsome evergreen shrub and it was widely grown by Southern nursery growers for use in both commercial and residential landscapes.  Aronia melanocarpa is not closely related to Photinia fraseri.

      Common names for aronia in languages other than English are:
            Danish: surbær
            German: apfelbeeren
            Icelandic: logalauf
            Latvian: aronijas
            Polish: aronia
            Russian: арония 
            Swedish: aronior
            Ukrainian: горобина чорноплідна 
            Upper Sorbian: slowčinowa aronija
            Welsh: aeron tagu

References:

Campbell, C.S., R.C. Evans, D.R. Morgan, T.A. Dickinson, and M.P. Arsenault. 2007. Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history. Plant Systematics and Evolution 266(1-2): 119-145.

Robertson, K.R., J.B. Phipps, J.R. Rohrer, and P.G. Smith. 1991. A synopsis of genera in Maloideae (Rosaceae). Systematic Botany 16(2): 376-394.

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      Please recommend this website http://aroniainamerica.blogspot.com/ to a friend, family member, or anyone who might be interested in aronia.
 

      Please post a comment in the box below.  To learn more about aronia, visit our website Everhart Horticulture Consulting.

Thank you,
Dr. Eldon Everhart

11 comments:

  1. I recently saw an article published (check pubmed.gov) by DL Maslov examining Aronia melanocarpa- it demonstrates that a tincture from the leaves effectively and significantly lowered blood glucose levels in diabetic and nondiabetic rats!

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  2. The chokeberry (aronia berry) is very high in antioxidants and has so many nutritional benefits. To find out more about these benefits visit www.superberries.com

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    Replies
    1. Rachael,

      Testimonials about the health benefits of aronia may lead you to believe that aronia will cure any ailment from cancer and heart disease to baldness and spider bites. But the truth is -- aronia is not a cure-all.

      The health benefits of antioxidants and aronia are well documented in medical research publications. Most of the research studies have been done on laboratory animals (rats) not on people. And most are relatively short term studies.

      It is always good to have a large dose of skepticism even when reading peer reviewed scientific journal articles. And testimonial from individual "believers" are little more than wishful thinking.

      The "placebo effect" is real and can be very strong. If you believe or want to believe that something will cure your ailments, it most likely will or at least you will think it has. Belief is very powerful.

      So beware of testimonials! Written or spoken statements extolling the virtue of any product are often worthless or just one person's opinion. Statements made by ordinary citizens and "celebrity endorsements" are often used to sell products. These sales-pitches can be very effective when selling products.

      For more information about the health benefits of aronia, read my post on this blog with that title -- Health benefits of aronia.

      Dr. Everhart

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  3. Thank you for such a clear and well-written post. I bought a book on shrub identification that sadly referred to the chokecherry as chokeberry in the index - so this is a better reference than a published book. Thanks!

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  4. Thank you for pointing out that, “…this is a better reference than a published book.” In fact, I have written a 44 page “book” about aronia. This booklet is not for sale. I give a “free” copy to each of my commercial aronia berry clients. It is full of essential information about commercial production, processing, and marketing of aronia berries.

    Each “want-to-be” commercial aronia berry grower that I consult with gets copy of my aronia growers’ guide as part of the consulting fee. Aronia consultations are available by telephone or in person. An aronia consultation usually takes about 3 to 5 hours depending on how much help is needed. I also provide follow-up support and assistance for as long as my clients need me and that’s usually at no additional cost.

    Dr. Eldon Everhart

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  5. Thank you! This was a very good comparison between the two plants. I now know that I have a chokecherry tree and not a chokeberry bush!

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  6. Replies
    1. Selena,

      This entire blog is about chokeberry. Please read my posts and you will discover what chokeberry is.

      Dr. Everhart

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  7. Thank you for this valuable information!

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  8. How can one tell the difference between purging buckthorn (toxic) and chokecherry? The seem to look *very* similar.

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    Replies
    1. Common names used for Rhamnus cathartica include buckthorn, common buckthorn, and purging buckthorn. Several characteristics can be used to tell the difference between buckthorn and aronia.

      The leaves of buckthorn plants are positioned on the stem in pairs. They are located across or nearly across from each other, with one leaf on one side and another leaf on the other side. This is known as an opposite leaf arrangement. The buds also have an opposite arrangement. Aronia has an alternate leaf arrangement where there is only one leaf at each point of attachment to the stem and they alternate from side to side on the stem.

      Buckthorn leaves are dark green and hang on late into the fall without changing color. Aronia leaves usually have red color in the fall.

      The mid-vein on buckthorn leafs are indented and runs from the base of the leaf to the leaf tip. Each leaf will have a total of 6 or 8 secondary veins that branch off of each side of the mid-vein. The secondary veins curve back and run somewhat parallel to the edge (margin) of the leaf.

      The twigs on buckthorn plants often end in short but sharp terminal thorns. These thorns are in the place where the terminal buds are found on most other plants – at the end of the twigs. Aronia has terminal leaf buds and does not have any thorns.

      The stem of each buckthorn berry attaches directly to the twig. Berries of aronia form a cluster. Each berry in the cluster has a short stem that is attached to one stem. That stem is attached directly to the twig.

      Buckthorn berries have a laxative effect on people. They are often classified as mildly poisonous to people. The berries are readily eaten by birds, which disperse the seeds in their droppings.

      Buckthorn is native to Eurasia. It was introduced into North America as an ornamental landscaping plant. Unfortunately, it has naturalized and become a problem in parts of Canada and the United States. Its dense growth crowds out native plants.

      Here is the link to a website with more information about buckthorn --http://www.nps.gov/plants/alien/fact/rhca1.htm

      Let me know if this helps.

      Eldon

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