The Park is a Site of Nature Conservation Importance Grade II. The most interesting part, from a wildlife point of view, is Parkland Walk, which borders the railway line along the western margin - running along the eastern side of the East Coast Main Line. It is a Local Nature Reserve and an Ecological Corridor.
A report and pictures of some of the flora follows. It's a pity nothing is made of the wildlife value in the park guide downloadable here:
According to the Management Plan that is also available here 'The Parkland Walk Local Nature Reserve is a footpath and cycle path running along the disused railway line from Alexandra Palace to Finsbury Park. [It] has been completely re-landscaped as part of the [park] restoration project. The area underwent complete site clearance and infill and mounding was achieved using the dredged material from the lake. A new footpath and cycle path was ..... constructed and native trees, meadow grasses and flowers were introduced.'
The walk starts at the Stroud Green Road gate by the railway bridge. Here a probably 'self-sown' Fig (Ficus carica) was holding its own against planted Berberis.
Looking north across characteristic vegetation of Mugwort, Bird's-foot Trefoil, Yarrow, Ox-eye Daisy and Clovers.
Many of the other species found are common components of vegetation assemblages around where I live in Barnehurst (SE London), including Field Bindweed, Ribwort Plantain, Teasel, White and Red Clover, Lesser Trefoil, Black Medick, Spear Thistle, Evergreen Alkanet, Bristly Ox-tongue, Old Man's Beard, Broad-leaved Everlasting Pea and Creeping Cinquefoil.
LASHINGS OF LEGUMES
This Spanish Broom (Spartium junceum) might be self sown, or may have survived removal of some shrubs due to anti-social behaviour problems (there's a reference to this development in the Management Plan). There's a patch of Comfrey behind it on the left. Contrast the bank with the mown grass beyond.
At the top of the bank above this were three plants of Tufted Vetch (Vicia cracca)- the largest seen here to the right of a Creeping Thistle.
A highlight, given I've been looking out for it everywhere I've been lately (with no success hitherto), was this solitary specimen of strongly red-purple flowered Zigzag Clover (Trifolium medium), growing amongst White Clover and Bird's-foot Trefoil.
This Tall Melilot (Melilotus altissima) was only 6" high, presumably struggling in very poor soil.
Inside the railway fence, heading north, were several Goat's-rue (Galega officinalis).
At the far north end of this part of the site, on a bank to the right of the footbridge over the ECML, that accesses the continuation of the closed Alexandra Palace branch, were several Lucerne, this one growing next to Weld.
Also here was a fine patch of Common Toadflax
Other species found in very small numbers included Silverweed, Black Knapweed (2 - but may have been more that were not in flower and thus overlooked), Musk Mallow (a few inside the railway fence) and this Vervain (only one found - a very wiry plant that doesn't show up well in the photo).
More typical was Yarrow against a backdrop of Mugwort and grasses, with Ribwort Plantain seed heads - a pleasing symphony of green and white.
If you find yourself at Finsbury Park with an hour to spare, go and have a look.