Adventives and Invaders at Walker Riverside

A short round-up of a glorious Saturday morning spent botanising one of my favourite local sites.

It is no secret that I am a big fan of the messy, post-industrial yet incredibly diverse riverside park at Walker. Visiting for a few years now, I’ve already amassed a fairly respectable plant list for the site yet somehow, each visit continues to turn up something new. Things were no different on a visit this weekend with local botanist, Ho-Yin Wong.

Heading first for the marina at St. Peter’s Basin and it wasn’t long before colossal fleabane caught my eye growing in no-mans-land by the side of the road. Up here, Canadian Fleabane (Erigeron canadensis) tends to be the common species, so much so that I often walk past them without checking. That’ll teach me, this one turned out to be Gurnsey Fleabane (Erigeron sumatrensis) identified by its hairy phyllaries.

Reaching the basin itself, it was pleasing to see that the various areas of pavement and wasteground here had not been ‘tidied’ as so many places around here often are. Lots more Guernsey Fleabane was found, alongside two more invaders: Russian Vine (Fallopia baldschuanica) and Narrow-leaved Ragwort (Senecio inaequidens).

Rummaging around further, Canadian Fleabane (with glabrous phillaries) was eventually observed, alongside Oxford Ragwort (Senecio squalidus) with its conspicuous black bracts. As for the highlight among the native species, it was nice to catch Small-flowered Crane’s-bill (Geranium pusillum) still in bloom.

Making our way down to the track that runs along the North bank of the Tyne, the usual riverside flora remained conspicuous. Here, Black Horehound (Balotta nigra) remained in flower and several self-sown Italian Alder (Alnus cordata) were seen. Much more interesting, however, were two new additions to the ‘Walker list’ in Alexanders (Smyrnium olusatrum) and better still, White-stemmed Bramble (Rubus cockburnianus). The latter a Chinese endemic long known from the riverside here yet annoyingly, one which I have struggled to find, until now.

Moving on to the site of the old tar works and a real hotchpotch of interesting plants appeared in quick succession. Clustered Bellflower (Campanula glomerata) remained in bloom, as did Wild Thyme (Thymus drucei), though sadly, the same could not be said for the Sainfoin (Onobrychis viciifolia) which grows here too. The Nasturtiums (Tropaeolum majus) dumped on site last summer also appear to be thriving, much to my surprise, and it was interesting to note Grey Alder (Alnus incana). Slightly further on we also encountered Hoary Ragwort (Jacobaea erucifolia).

Back down by the riverside and it was exciting to record both Hoary Mustard (Hirschfeldia incana) and Flattened Meadow Grass (Poa compressa) – both scarce species locally. As a matter of fact, it was thanks to the aforementioned grass that we chanced upon what would turn out to be the highlight of the day – a great clump of Blue Fleabane (Erigeron acris). More on that one in an upcoming post.

Soon it was head off, though not before a quick excursion along the wooded cycleway further up the bank. Here, Chinese Bramble (Rubus tricolor) was a bit of a curiosity as was what I think is Box-leaved Honeysuckle (Lonicera pileata). Having watched it with frustration for two years now, I was also happy to make some headway with the ‘unusual’ spurge that grows here. Looking closer, it appears this might be Balkan Spurge (Euphorbia oblongata), identification made easier by the presence of fruit on this occasion.

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