longisporum Nelsen, Lücking & E.Navarro (2006) Haematomma fluorescens is a species of corticolous (bark-dwelling) and crustose lichen in the family Haematommataceae.

Found in the neotropics, it was formally described as a new species in 1995 by lichenologists Klaus Kalb and Bettina Staiger.

The type specimen was collected in the cordillera of Piribebuy in Paraguay; here it was found growing on the bark of Cinchona.

The specific epithet refers to the fluorescence observed when the lichen is shone with a UV light; this is caused by the secondary compound known as lichexanthone.

[3] Haematomma fluorescens has been reported to occur in Costa Rica, Argentina, Bolivia, Brazil, Paraguay, and Venezuela.