Red-berried Elder (Sambucus racemosa) / Cutleaf staghorn sumac (Rhus typhina 'Laciniata.')

There has been a mystery at the Richard St. Barbe Baker Afforestation Area in two different locations. There have been found two woody species that looked like they could be identified as Red-berried Elder (Sambucus racemosa) / Cutleaf staghorn sumac (Rhus typhina 'Laciniata') in 2020.

je9h mentions that for Red-Berried Elders "The laciniate leaf edges suggest either a planted or escaped horticultural selection. Both S. racemosa and S. nigra have such forms but S. racemosa has orange-brown pith in the branches and red mature fruits, while S. nigra has white pith and purple-black mature fruits."

Now then going back to the two sites in 2021, there seems to be only leaf shapes common to Sambucus racemosa and the cut leaf variety is not able to be found.

On looking at this particular observation, there does seem to be two leaf shapes for the same plant. https://www.inaturalist.org/observations/57871847

So, on doing some conversations with aaron881 on this page comparing their "cut-leaf / deeply lobed" variety - which was so very similar to my "cut-leaf / deeply lobed" observation - https://inaturalist.ca/observations/90828644 there was some interesting developments.

Looking online there is a scientific journal which states :"A variety with deeply dissected leaflets (var. laciniata) is noted in a number of local floras (e.g. Wolley-Dod 1937; Lousley 1976). The inheritance of the finely divided leaf character in Sambucus nigra was shown to be governed by a single recessive gene by Tobutt (1992). A similar genetic basis was found for the finely divided leaves of Sambucus canadensis (var. acutiloba) (Way 1965)."

But now the weird thing is....that even though I found my " laciniate / cut-leaf / deeply lobed" variety last year in the summer of 2020. I have really been searching and searching for it this year - the summer of 2021, and cannot find the " laciniate / cut-leaf / deeply lobed" specimen to make a follow-up observation of it this year, so maybe the leaf shape also has something to do with the environment from year to year if that is possible - and yet I thought there were additional elders in the two areas.

This website about ornamental elderberries -https://davesgarden.com/guides/articles/view/1061- also shows an elderberry "cut-leaf / deeply lobed" similar to the leaf which aaron881 and myself found in different locations.

Now then the question comes is for elderberries if there is ever a case where a sambucus plant has leaves which look one way in one year, and another appearance in another year--like where the leaves of the salsify which is a biennial will have different leaf shapes from year one to year two.

It also turns out that S. nigra -with black berries - is a larger sized, non-suckering shrub reaching 6 m, while S. canadensis is commonly suckering in habit, from https://davesgarden.com/guides/articles/view/1061 The hybrid ‘Sutherland Gold' seems to resemble the " laciniate / cut-leaf / deeply lobed" which were seen in the year 2020. Though, as I say, not any " laciniate / cut-leaf / deeply lobed"" to be found in either of the two locations in 2021.

THE HERB SOCIETY OF AMERICA’S ESSENTIAL GUIDE TO ELDERBERRY https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjM5Y7TqdTyAhWmFlkFHQT0AAsQFnoECAIQAQ&url=https%3A%2F%2Fwww.herbsociety.org%2Ffile_download%2Finline%2Fa54e481a-e368-4414-af68-2e3d42bc0bec&usg=AOvVaw3ep7yrozUiZVx1j1hwyJ9Q
mentions that several cultivars of S. Niagra are available, and that there is an image of a leaf similar to the leaves in the observations shown in the Richard St. Barbe Baker Afforestation Area, and also the observation taken by aaron881. In the case of the afforestation area elderberry - the berries are red and not black as which S. Niagra would exhibit.

So, does anyone know if S. racemosa might have different leaf shapes for different years, and why the plant would have the typical standard leaf comparable to all other S.racemosa observations in 2021 and then some anomolous sightings with the " laciniate / cut-leaf / deeply lobed" variety of leaf appearing in 2020.

Afforestation area observations
https://inaturalist.ca/observations/91325167

The following appears to have two kinds of leaves on one plant.
https://www.inaturalist.org/observations/57871847

and a few more S. racemosa observations not included here which were taken in the Richard St. Barbe Baker Afforestation Area.

Posted on Αύγουστος 28, 2021 0632 ΜΜ by saskatoonafforestationareas