Rothm is used in conjunction with a flower, the Spanish Bluebell. However, it actually isn't Latin, but just an abbreviation for Rothmaler (Werner Hugo Paul Rothmaler). The official Latin/scientific name is Hyacinthoides hispanica. My guess is that "Chouard ex Rothm." refers to two people who did research on the plant.
On the .net blog you refer to, my guess is the author chose it because his family name is Roth and given name initial is M., according to the domain's WHOIS.
My appraisal is for reg. fee. The meaning of the name probably doesn't give it any value, but I do think it sounds neat.