When Orthophytum vidaliorum was described, Ribeiro and Paula (2010) discussed its morphological relationship with Orthophytum itambense. It was emphasized that these species share similar habitat, plant size, leaves, inflorescence and flower structure. Moreover, they state that Orthophytum vidaliorum is also closely related to Orthophytum supthutii which was recently synonymized under Lapanthus duartei. In the same article the authors also mentioned that Orthophytum vidaliorum could be included in a different and unpublished genus proposed by Louzada (2008) in his master’s thesis, which later was validly published under the name Lapanthus by Louzada and Versieux (2010).

Besides, some morphological characters such as the rosette shape, the morphology and size of the leaves and the size of the flowers support the decision to include Orthophytum vidaliorum under Lapanthus.

Identification key for the species of Lapanthus

Lapanthus vidaliorum occurs in the southernmost part of the Espinhaço Range, in an iron–rich region called Quadrilátero Ferrífero (Iron Quadrangle) in the Brazilian state of Minas Gerais. Although it occurs in an iron–rich area, Lapanthus vidaliorum was found inhabiting quartizitic–sandstone rocky outcrops (Ribeiro and Paula 2010) The present combination extends the genus distribution approximately 120 km southward (Fig. 3).

Lapanthus vidaliorum is an endangered species, known only from the type–population, which is small in number of individuals, being about 3.5 kilometers from the iron ore mine Capanema and surrounded by an Eucalyptus plantation. Therefore, according to IUCN (2001) criteria this species is considered critically endangered (criteria B2a).