Mandoniella is likely to be confused with Rhynchostegium; both species have similar leaves that are smooth, not plicate, a costa ending in a spine, and an often twisted apex. The former is distinguishing by the subterete branches, and the erect capsules, the latter by the ± complanate branches and inclined capsules. The generic name is in honor of Gilbert Mandon (1799-1867), a mining engineer who was among the first important plant collectors in Bolivia. This monospecific genus was originally described as Helicodontium by Williams (1909), and later given generic rank by Herzog (1916); Buck (1981) accepted this taxon in a review of several taxa with erect capsules. The generic name is in honor of Gilbert Mandon (1799-1867), a mining engineer who was among the first important plant collectors in Bolivia.
Mandoniella es un género monoespecífico, representado por M. spicatinervia (R.S. Williams) Herzog. Este género probablemente sea confundido con Rhynchostegium; ambos tienen hojas similares lisas, no plegadas, costa terminando en una espina y a menudo ápices torcidos. La primera especie se distingue por las ramas subteretes y las cápsulas erectas, la segunda se caracteriza por tener ramas ± comprimidas y cápsulas inclinadas. El nombre genérico hace honor a Gilbert Mandon (1799-1867), un ingeniero minero considerado uno de los primeros colectores importantes de plantas en Bolivia. El espécimen tipo fue colectado en Pelechuco por Williams en 1902.