Asparagus tongs have a wide, flat bottom tong with a hinged, rounded top tong that allows you to scoop up and serve several spears at one time. This traditional piece of silver service was typically made from sterling silver. There were also other styles that had two long narrow tongs rather than the wider version. The hooded asparagus tongs are one piece piece rather than two hinged together with a rolled edge on the back where the handle attaches. The "hood" keeps the asparagus from falling off the server.
Asparagus tongs were part of the formal table setting in the mid 18th to the 19th century. Some manufactures continued to make silver plate versions well into the 20th century. You can still find them on Ebay, Etsy and places like Replacements.com.
As far a specialty serve-ware goes, asparagus tongs were pretty practical. The fact that you could neatly pick up, drain, then transfer several asparagus spears to a guests plate is pretty sweet.
There was at least one patent for an asparagus server issued to Emma Meta Underhill, dated April 17, 1919, Patent number 54.150.