Trichothalamus Spreng., Anleit. Kenntn. Gew.

Eriksson, Torsten, Persson, Nannie L. & Smedmark, Jenny E. E., 2022, What is Potentilla? A phylogeny-based taxonomy for Potentillinae (Rosaceae), TAXON 71 (3), pp. 493-505 : 497

Trichothalamus Spreng., Anleit. Kenntn. Gew. , ed. 2, 2: 864. 1818

– Type (designated here): Trichothalamus caulescens (L.) Spreng. (≡ Potentilla caulescens L.).

A number of genera were listed under the “Potentilleen” heading in Kurt Sprengel’ s Kenntniss der Gewächse ( Sprengel, 1818): Potentilla , Tormentilla , Comarum , as well as his new genus Trichothalamus . The species belonging to Trichothalamus were described as having stiff hairs in the centre of the flower, among the nutlets. Sprengel listed six species from the Alba clade: Potentilla caulescens , P. clusiana , P. nivalis (as P. lupinoides ), P. valderia , P. alchemilloides and P. nitida , as well as P. tridentata , which we now know is Sibbaldia tridentata (or Sibbaldiopsis tridentata ) in the Fragariinae clade ( Eriksson & al., 2003, 2015; Feng & al., 2017), making it a polyphyletic genus. Later, a few more species were added based on this technical character, but as no type has previously been designated, one in the original list should be selected. Trichothalamus caulescens belongs to the Alba clade.