Pinus

Taxonomy

Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnosperms
Class: Pinopsida
Subclass : Pinidae
Order: Pinales
Family: Pinaceae
Subfamily: Pinoideae
Tribe: Pineae
Genus: Pinus

Species

Notes

There is no actual consensus regarding the taxonomy of mountain pines (P. mugo complex). The “historical” taxonomy which is retained here is based on a single species with three subspecies. This choice is supported by the genetic proximity of the three taxa (Sokołowska et al., 2021):

P. mugo subsp. mugo Turra, 1764;
P. mugo subsp. rotundata (Link) Janch. & H.Neumayer, 1942;
P. mugo subsp. uncinata (Ramond ex DC.) Domin, 1935.

Other sources such as the latest version of TAXREF recognizes each of the three taxa but considers them as distinct species:

P. mugo Turra, 1764;
P. rotundata Link, 1830;
P. uncinata Ramond ex DC., 1805.

POWO considers P. mugo and P. uncinata as two distinct species, and treats P. rotundata as a synonym of P. uncinata. This distinction somewhat make sense due to the lesser genetic proximity between P. mugo and P. uncinata than between P. uncinata and P. rotundata (Cantegrel, 2017).

However, POWO also recognizes an additional subspecies for P. uncinata - P. uncinata subsp. uliginosa (G.E.Neumann) Businský, 2006 - which adds further complexity to the problem. It is challenging to determine which populations this subspecies refers to, because P. uliginosa is often considered a synonym of P. rotundata by other sources, but not there.

Putting aside aside the synonymization of P. rotundata with P. uncinata as done by POWO, the correspondence between the different sources would be as follows:

Taxon	Historical	TAXREF	POWO
P. mugo	P. mugo subsp. mugo Turra, 1765	P. mugo Turra, 1764	P. mugo Turra, 1764
P. rotundata	P. mugo subsp. rotundata (Link) Janch. & H.Neumayer, 1942	P. rotundata Link, 1830	P. uncinata subsp. uliginosa (G.E.Neumann) Businský, 2006
P. uncinata	P. mugo subsp. uncinata (Ramond ex DC.) Domin, 1935	P. uncinata Ramond ex DC., 1805	P. uncinata subsp. uncinata Ramond ex DC., 1805

Sources

Cantegrel, R. (2017). Les Pins de montagne (Pinus uncinata Ram, P. mughus Scop., et consorts) du Jura aux Préalpes orientales en passant par la Lorraine et la Bohême. Revue forestière française, 69(6), 587-632. https://doi.org/10.4267/2042/68188
Sokołowska, J., Fuchs, H., & Celiński, K. (2021). New Insight into Taxonomy of European Mountain Pines, Pinus mugo Complex, Based on Complete Chloroplast Genomes Sequencing. Plants, 10(7), 1331. https://doi.org/10.3390/plants10071331