Plant watcher are an industrious lot and they like nothing better than share their observations with others, in book form if possible. P.M.E. Gevers Deynoot (1816-60) studied law in Leiden, not very successfully as he never specialized and never practiced, was shunned for his social disgrace, he was married to a woman of low social standing (like Thomas DeQuincey!), came to Utrecht for a year, does not seen to have done much other then walk around and botanize, he published his results as 'The Flora van Utrecht' in 1843 and moved on to Nijmegen. He never seems to have had a proper job and was therefore probably 'in money' and his double last name gives a clue to where that came from. Not much else is known. The foreword to my 1970 reprint states that his Latin was good, his plant knowledge sufficient but his taxonomy outdated. The area he covered was the radius of a two hour walk from the city of Utrecht. Depending on which way you go the first 30 to 60 minutes of those two hours would keep you within built environment. A number of plant he mentions haven't been seen here for a century, some that are common now, like Giant Hogweed (see below), he found only at one place.
If you are into this kind of stuff, if you know the area it is about, this little book can really transport you to another century. Most of my direct environment was still wet and peaty in those days, waiting for irrigation in the early 20th century, but when I look up plants that grow in my street now (greater celandine for instance) I learn that Gevers Deynoot observed them in the bushes just outside of the city, that is not very exact but it could be right here. This continuency, even if only imagined, makes looking at plants even more interesting.
