Aspen Catkins – male or female?

0391aspen-catkinsClick image to view

Remember 9th of March when John Parrott spoke about aspen?

0384aspen-catkinsClick image to view

On 16th May Marion & Phil spotted a single aspen tree with catkins in a collection of over 60 ramets (stems) mixed with birch, scots pine and alder.  This ratio may be in line with the rarity of Aspen setting seed.

0374aspen-catkin-branchesClick image to view

The only branches showing catkins were quite high up and digiscoping was resorted to in order to get images.

North Highland Forest Trust had information, from which I have purloined these images. (Note from 2018; the NHFT has no website.)


Female Catkin


Male Catkin

I will try to watch the catkins develop to ascertain which sex they are. (Note from 2018; internet searches show the very clear differences between male and female aspen catkins. Male look quite red. Female are green going whitish.)

To confirm which catkin is which sex NHFT advice is to break off a small branch/twig, place it in water so it survives, and watch the catkins develop.

The location of this aspen tree is NH 59692 89843, +/- 7metres, so says the GPS.

That is above Ardgay, Sutherland on Landranger sheet 21.

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4 Responses to “Aspen Catkins – male or female?”

  1. Admin says:

    Thanks hutchinson, presumably this tree(s) will be quite visible, but can you give an approximate grid ref NH 67x 89x.

    I wonder if any seed is visible on the smaller branches.

  2. hutchinson says:

    are you aware of large aspen in oakwoods south of spinngdale and the young aspen that are growing some 10 metres from it.

  3. Admin says:

    Here is a progress report for spotting the aspen flowers:

    The original spot was on 16th May and the single tree’s flowers appeared immature, but were too high for close examination. Pictures above.

    On 25th May a stand of 8 trees was spotted about 1km away where all the trees had catkins – suspected to be female. We managed to collect a nice flower which was stood in water.

    Here is a look at the catkins seen on 25th May:

    And a further 4 days on, 29th May:

    Finally, the last word on these catkins – these in our dish of water seem played out, those out on the trees are still visible but through the new leaves only just.

    1st June view of catkins

    These aspen catkins were confirmed as female by Rob Lee from Alba Seeds who visited the site. It seems this flush of catkins is just about the first in 15 years.

    Our catkins look like having no possibility of fertilisation from pollen, a least no male catkins are nearby. The fluffy material helps catch pollen and our catkins just got fluffy to no good purpose.

    What should happen is that each ‘capsule’ visible in the early catkins would develop one seed. Should that happen it – the capsule – would enlarge, deform, become yellowish and mature to produce the seed. The catkin seen on 25th May shows this, and a potentially tiny seed was seen, but it had no chance of maturing.

    Why had not all the capsules become fertilised?

  4. John Parrott says:

    From John Parrott, 17th May 2010


    Annual General Meeting and
    Field Trip

    Saturday 29th May 2010
    Killiecrankie, Perthshire

    You are cordially invited to attend the Highland Aspen Group AGM in Highland Perthshire on Saturday 29th May 2010.

    The meeting will include a short indoor session, followed by a visit to nearby Aspen stands above Killiecrankie and a few miles away at Old Struan on Atholl Estate.

    Provisional programme (with approximate timings) as follows:

    11.00 Coffee, Killiecrankie Village Hall
    11.15 AGM
    11.45 Illustrated talk by Rick Worrell:
    Aspen: suckers, seed and sex,
    12.30 Packed lunch – in the Hall if wet OR
    12.30 Travel to site, and have lunch al fresco
    13.00 Site visits
    15.30 Disperse

    Please bring a packed lunch (including a drink), and suitable outdoor clothing.

    If you wish to attend, please contact Victor Clements or John Parrott so we’ll have an idea of numbers, and can circulate a list of likely participants before the meeting, to help car-sharing.
    Killiecrankie lies mid way between Blair Atholl and Pitlochry, and is well signposted just off the A9. Come in to the village and the Village Hall is relatively easy to find, on the main street. Parking space at the hall and at the sites is restricted, so if you
    can share transport, please do so.

    If you need further information, please contact: 01456 486426 01540 661962 01887 829220