Not to be confused with :
Wild Parsley, Garden Parsley nor with
Stone Parsley or Upright Hedge-Parsley [plants of similar names, but all belonging to the Umbellifer/Apiaceae Family, and nearly all have non-yellow flowers].
Not so easily confused with: Garden Parsley, which has greenish-yellow flowers, is less than 18 inches high and has shiny leaves that are highly crinkled (like parsly, which is what it is). Despite the similarity in names, Garden Parsley belongs to a different Genus, Petroselinium, which despite the name, contains no Selenium of note within it (a slightly different spelling too).
Not to be confused with : Alexanders which is another yellow-flowered Umbellifer, but Alexanders has hemi-spherical umbels, inflated bracts, and leaves of a darker and shinier green that end in triplets of even size.
The only other yellow-flowered umbellifers that it could be mistaken for are Fennel and
Hog's Fennel, which both have wispy wiry stem leaves that in no way resemble normal flat leaves, or
Pepper-saxifrage which has much narrower pinnate leaves (including the terminal leaflet).
There is also a
Garden Parsnip (Pastinaca Sativa ssp. hortensis) with which it may be mistaken, but that has rather few and short strainght hairs rather than the long and wavy ones of Wild Parsnip.
The one remaining possibility is that it is the sub-species Pastinaca sativa subsp. urens but that is only found in five hectads well South and East of Birmingham.
Slight resemblance to : Rock Samphire [an atypical umbellifer].
Wild Parsley occupies bare places, grassy places, roadsides, and old sand dunes, but it will also grow well away from the sea. It is pungent when crushed, smelling unpleasant.
COUMARINS and FUROCOUMARINS
Tissues of Wild Parsnip grown in culture produced several coumarins and furocoumarins, such as Psoralen,
Isopimpinellin, Umbelliferone and Xanthotoxin. Because of its phototoxicity, only 2% of bergapten is allowed in perfumes and tanning lotions (where it absorbs harmful UV).
Wild Parsnip infected by certain plant pathogenic fusaria (a fungus) produce
Trichothecenes, which are plant phytotoxins and potent inhibitors of protein synthesis in eukaryotes. The roots of Wild Parsnip, when so infected, accumulates high levels of fungitoxic furocoumarins, mainly Xanthotoxin (aka Mothoxysalen and 8-methoxyPsoralen) and Angelicin.