The Wild Parsnip (Pastinaca sativa) grows on the borders of
ploughed fields and about hedgerows, being generally hairy, whilst
the Garden Parsnip is smooth,  with taller stems, and leaves of
a yellowish-green colour. This cultivated Parsnip has been produced
as a vegetable since Roman times. The roots furnish a good deal of
starch, and are very nutritious for warming and fattening, but when
long in the ground they
are called in some places Madnip, and are
said to cause insanity.
Chemically, they contain also albumen, sugar, pectose, dextrin, fat,
cellulose, mineral matters, and water, but less sugar than turnips or
carrots. The volatile oil with which the cultivated root is furnished
causes it to disagree with persons of delicate stomach; otherwise it
is highly nutritive, and makes a capital supplement to salt fish, in
Lent. The seeds of the wild Parsnip (quite a common plant) are
aromatic, and are kept by druggists. They have been found curative
in ague, and for intermittent fever, by their volatile oil, or by its
essence given as a medicine. But the seeds of the garden Parsnip,
which are easier to get, though not nearly so efficacious, are often
substituted at the shops. A decoction of the wild root is good for a
sluggish liver, and in passive jaundice.
In Gerard's time, Parsnips were known as Mypes. Marmalade made
with the roots, and a small quantity of sugar, will improve the
appetite, and serve as a restorative to invalids.
From the mashed roots of the wild Parsnip in some parts of Ireland,
when boiled with hops, the peasants brew a beer. In Scotland a good
dish is prepared from Parsnips and potatoes, cooked and beaten
together, with butter. Parsnip wine, when properly concocted, is
particularly exhilarating and refreshing.
The Water Parsnip (spelt also in old Herbals, Pasnep, and Pastnip,
and called Sium) is an umbelliferous plant,  common by the
sides of rivers, lakes, and ditches, with tender leaves which are a
sovereign remedy against gravel in the kidney, and stone in the
bladder. It is known also as Apium nodiflorum, from apon,
water, and contains pastinacina, in common with the wild Parsnip.
This is a volatile alkaloid which is not poisonous, and is thought to
be almost identical with ammonia. The fresh juice, in doses of one,
two, or three tablespoonfuls, twice a day, is of curative effect for
scrofulous eruptions on the face, neck, and other parts of children.
Dr. Withering tells of a child, aged six years, who was thus cured of
an obstinate and otherwise intractable skin disease. The juice may
be readily mixed with milk, and does not disagree in any way.