Abies equi-trojani

Today’s entry was written by Raakel Toppila, who recently completed the Longwood Graduate Program in Public Horticulture. She’s helping our Garden assess some collections management tools. Raakel writes:

Thank you to James Gaither (aka J.G. in S.F.@Flickr) for today’s photographs of Abies equi-trojani (photo 1 | photo 2 | set).

The curious name of this species comes from its occurrence on Mount Ida of Trojan War fame in the northwest of Turkey. Equ, being the Latin word for horse, is likely reference to the legendary horse that brought victory to the Greeks. The distribution of the Trojan fir is limited to a total area of about 3600 ha, with a number of isolated populations ranging in size from 120 ha to 2400 ha in the northwest of Turkey. The tree is valued for its rapid growth rate and high quality timber which has threatened existing populations thanks to illegal logging. That, along with pollution and tourism, has resulted in the decline and endangerment of the species.

Priority was placed on its protection in a national plan for the In Situ Conservation of Plant
Genetic Diversity in Turkey. But first, it had to be determined what exactly the target for protection was. Abies, along with many other genera, are known for their *ahem* promiscuity or interspecific hybridization.

The exact taxonomic placement of this particular fir is debated. It been treated as its own species and as a variety or subspecies of both Abies cephalonica and Abies nordmanniana. Additionally, it is remarkably similar to Abies bornmuelleriana which has also been treated as a subspecies and variety of Abies nordmanniana. To complicate things, its morphological intermediacy, hybrid vigour qualities and pollen sterility suggest that it is a hybrid. Recent work (PDF) using DNA fingerprinting techniques have indeed identified three separate species, Abies nordmanniana, Abies bornmuelleriana and Abies equi-trojani. Protection has been placed on the two latter species which have a limited distribution compared to Abies nordmanniana.

Abies equi-trojani
Abies equi-trojani

11 responses to “Abies equi-trojani”

  1. Ron B

    Can you expand on that last paragraph a bit? Pollen sterility, in this instance means it does not cross well with other species? Or it has partly sterile pollen resulting in substandard production of fertile seed?
    Your recitation of its apparent hybrid characters is followed immediately by the statement that DNA work has shown it to be a species, without any remarks addressing the discrepancy. What is the conclusion?

  2. Janet Ackelson

    Thanks for using both photos to give an idea of what the tree itself looks like, as well as the close-up.

  3. Toinette Lippe

    Actually, the Latin for “horse” is “equus,” not “equ.”

  4. Sara

    Awesome – the info, the photo. Especially the info – written in a style that the *ahem* total novice can understand. Thank you.
    I want a Christmas tree like that in my front yard!

  5. F. Joseph Peabody

    Comment for Toinette Lippe (and others who might be interested):
    It is true that the Latin word for horse is equus (nominative singular), but the “stem” of the noun is “equ-” to which the various “endings” are added depending on the number and case. This noun is in the second declension, therefore it is declined as follows:
    equus – nominative singular – the subject of a sentence
    (The horse is in the barn.)
    equi – genitive singular – used to indicate possesive
    (The tail of the horse has been cut.)
    equo – dative singular – indirect object
    (Bring some water to the horse.)
    equum – accusative singular – direct object
    (The cowboy rode the horse all day.)
    equo – ablative singular – used after most prepositions
    (The boy jumped on the horse.)
    So the bottom line is that it is perfectly appropriate to use the “stem” (equ-) in forming Latin names for plants, and I think that was the intent of the author in stating that Equ is the Latin “word” for horse.

  6. Daniel Mosquin

    Ron, Raakel will be replying after she gathers a bit more information.

  7. Elizabeth

    First of all, Raakel is going to be fantastic as a “Public Horticulturist”. Her writing shows her friendly personal relationship to plants and that is so important when you are trying to get people to relate to plants.
    Secondly, I have been reading this blog for a couple of years now and seen and learned about so many amazing plants. There have been many I’ve daydreamed about having in my own garden but this is the first time I’ve wanted to do something about it. I live in Western Colorado and the growing conditions are similar to Turkey, depending, of course, on where in Turkey. Could I get some seed? Or is there somewhere I could get some seed? I’d love to grow one here.
    Daniel, keep up the good work. I really enjoy Botany Photo of the Day.

  8. elizabeth airhart

    ti’s a beautiful tree
    what kind of birds like this tree
    p.s. my horse paid 12.50 at the race track ron
    my parents did not approve of my reading
    ahems when in school
    daylight time in the u s of a sring ahead
    after one monster snow storm after another
    i hope every one has a lovely spring bon jour

  9. Daniel Mosquin

    Elizabeth, it is in cultivation, so it shouldn’t be impossible to find. Here it is listed on the Missouri Botanical Garden Plant Finder site: Abies equi-trojani.
    The University of Idaho Center for Forest Nursery and Seedling Research sometimes has seedling stock, but it looks like it is sold out at the moment. I’ve found this company as a source for seeds, but I’ve had no interaction with them and this isn’t an endorsement.

  10. Ron B

    5 nurseries were listed by Hill, Narizny The Plant LocatorWestern Region (2004, Black-Eyed Susans, Portland).

  11. Raakel

    Hi Ron,
    A 1958 morphology and pollen study on Abies equi-trojani (out of Turkey) and a separate 1959 pollen study on the species (out of France) revealed pollen sterility which is suggestive of a hybrid origin. I could not get access to these articles in English. Though numerous English papers make reference to the studies, they do not provide more detail.
    With the recent advances made in phylogenetics using molecular markers, it is now possible to answer questions about plant taxonomy which may be more revealing than morphological and pollen studies. In the 2008 reference that I cite, the authors use DNA markers to determine differentiation between three species that are regarded as belonging to the nordmanniana fir complex. Based on their results, they conclude that there are in fact three distinct species. However, their study reveals that the three species share a large number of molecular markers, (A. equi-trojani and A. bornmuelleriana sharing 71.85% of markers and A. equi-trojani and A. nordmanniana sharing 72.22%) despite the fact that the three species’ populations do not overlap. The large number of shared markers suggests that the three species may have evolved from a common ancestor that once had a more continuous distribution in the region. It may also suggest introgression, or the repeated backcrossing of an interspecific hybrid with its parent species. Introgression differs from hybridization, however, depending on the degree of introgression the consequences in plants may be similar. For example, a number of studies reveal low pollen viability in first generation hybrids with increasing pollen viability (close to that of parental species) with repeated backcrossing (or introgression) with parental species over a number of generations. So, introgression may account for the shared DNA molecular markers revealed in the 2008 study, as well as the hybrid characteristics identified in studies from the 1950’s.

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