Skye and Raasay populations of Agrimonia have caused confusion for a very long time with different recorders reporting the same populations as Agrimonia eupatoria (Agrimony) or Agrimonia procera (Fragrant Agrimony). Specimens I have shown to experienced botanists have divided them equally, and in one case led to vociferous claims that anyone saying it was the other species from his determination was just wrong! (He was wrong, it turns out.)
On Sunday I collected specimens from widespread sites on Skye – in NG44, NG45 and NG51. With minor variations, they are all the same – and it is my view that all known populations on Skye & Raasay are the same.
I copied and took with me the relevant pages of
- Sybil J Roles Flora of the British Isles Illustrations Part II 1960
- Tim C G Rich & A Clive Jermy Plant Crib 1998
- Clive Stace New Flora of the British Isles 4th Edition 2019
- Peter Sell & Gina Murrell Flora of Great Britain and Ireland Vol 2 2014
I also prepared a list of differences mostly, but not exclusively, from the detailed accounts in Sell & Murrell. I propose to go through these for the sake of posterity. Feel free to jump to the conclusions at the end!
Habit
Sell & Murrell: A. procera height to 120cm. A. eupatoria var. eupatoria to 35cm; var major to 150cm known only from Norfolk and Cambridgeshire and probably introduced. Stace: A. eupatoria to 100cm, A. procera not stated to be different. Rich & Jermy warn of large glandular forms of A. eupatoria from County Durham that have been mistaken for A. procera.
Skye plants to 150cm

Marker is at 150cm
A. eupatoria leaves often in a basal rosette, cauline few; A. procera leaves not forming a basal rosette, fairly frequent on stem. Skye plants have no basal rosette and leafy stems.
Leaves
A. procera green both sides. A. eupatoria dark green above, white/greyish below.
Skye plants:

Upper and lower surfaces
A. eupatoria leaves glabrous on upper surface, A. procera not stated. Skye plants – some leaves have hairs on the upper surface.
I shall return to the shining glands at the end….
Stipules
A. eupatoria leaf-like, A. procera large clasping and deeply dentate. Illustration of A. procera from Roles:

Skye plants:

Petals
A. eupatoria usually not emarginate, A. procera emarginate. Skye plants always emarginate.
Fruits
A. procera hypanthium including bristles c. 11 x 11mm, turbinate (top-shaped), broad shallow grooves for about half its length, lowest bristles distinctly deflexed. A. eupatoria hypanthium 7-10 x 5-7mm, obconical, grooved throughout its length, outer bristles ascending, patent or deflexed. Rich & Jermy warn that the hypanthium may lose its characteristic bell shape in forms of A. procera in which a single seed is formed instead of the normal two, making it appear obconical. Illustrations from Stace:

A. procera above, A. eupatoria below.
Skye plants:

Skye fruit
I rest my case. Skye plants are Agrimonia procera (Fragrant Agrimony). What is interesting is that the shining glands on the underside of the leaves are not very frequent and hence the plants are not fragrant, at least by this time of the year. Given that the presence of numerous shining glands as opposed to nil or few is one of the main characteristics used by all floras to distinguish these two species, it is unsurprising that there has been confusion in the past.