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Angraecum rutenbergianum and A. didieri

Discussion in 'Orchid Species' started by naoki, Aug 15, 2020.

  1. naoki

    naoki Well-Known Member

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    Location:
    Fairbanks, Alaska
    I got these two plants labelled as A. rutenbergianum (Ar) and A. didieri (Ad) from Madagascar Import of Louisiana Orchid Connection. I posted an earlier photos of this particular Ad in this thread. There are quite a few differences between these two plants. The differences of these two species have been debated, but I usually end up confused. So I'm not sure if these are even correctly ID'd.

    Measurements (Length x width in mm):

    A. rutenbergianum
    • DS 25x8
    • LS 27x8
    • petal 24x4
    • Lip 31x21
    • spur 140 (length)
    • Ovary 40x3
    • peduncle 6 (length)
    • leaf 70x7

    A. didieri
    • DS 38x9
    • LS 38x7
    • petal 32x5
    • Lip 35x24
    • spur 145 (length)
    • Ovary 28x5
    • peduncle 16 (length)
    • leaf 60x14

    Ar (right), Ad (left)
    P7287264.jpg
    P7287266.jpg

    Note Ad has much longer internodes (distance between the leaves). Also Ar has a longer and skinnier ovary. But Ar has shorter peduncle (the stem between the stem and ovary).
    Ar (left), Ad (right)
    P7287393.jpg

    The angles of the lateral sepals seem different. Ar has a flatter lip near the base.
    Ar
    P7287275.jpg

    Ad
    P7287338.jpg

    From this angle, you can see the difference in the curvature of the lip near the column.
    Ar
    P7287293.jpg

    Ad
    P7287347.jpg

    Ad's flower is older, so the anther cap is a bit shrivelled, so I'm not sure if there is a difference in the shape. The angles are slightly different, but there may be slight difference in column shape. Ad seems to have side-lobes stretching down further.
    Ar
    P7287302.jpg

    Ad
    P7287356.jpg

    Ar
    P7287311.jpg

    Ad
    P7287365.jpg

    Ar has much smoother root texture. These are newer roots which developed in my grow tent, so they are in the same environment, and retained the original characteristics at the time of import.
    Ar
    P7287320.jpg

    Ad
    P7287374.jpg

    The leaf shapes are really different with narrower leaves of Ar. The color and texture are different. Ad has pits like things on the leaves, and they are more noticable.
    Ar
    P7287329.jpg

    Ad
    P7287383.jpg
     
    Last edited: Aug 15, 2020
    W. Malewa, J E, RustyExotics and 4 others like this.