Phylogenetic Relationships in Primula L. and Related Genera (Primulaceae) Based on Noncoding Chloroplast DNA

We sequenced the trnL and rpl16 introns of the chloroplast DNA from 95 of the ca. 425 species (30 of 37 sections, seven of eight subgenera) of Primula L. in order to reconstruct the phylogenetic history of the group. Among the 24 additional taxa sampled are representatives of all genera that are likely to be embedded in Primula, as well as outgroups from the Maesaceae, Theophrastaceae, and Myrsinaceae. In the strict consensus of the most parsimonious trees, Primula and the genera embedded in it (Dionysia Fenzl., Sredinskya Stein Fedorov, Dodecatheon L., and Cortusa L.) are sister to a clade of several genera previously suspected to be embedded in Primula (Hottonia L., Omphalogramma Franchet Franch., and Soldanella L.). In recognition of this, two new rankless names are defined for these clades (/Primula and /Soldanella). Close relationships are inferred between Dionysia and Primula subgenus Sphondylia (Duby) Rupr., Sredinskya and Primula subgenus Primula, Dodecatheon and Primula subgenus Auriculastrum Schott, and Cortusa and Primula subgenus Auganthus (Link) Wendelbo. The largest subgenus, Aleuritia (Duby) Wendelbo, is dispersed among three clades that are not each other's closest relatives. Primula sections Muscarioides Balf. f., Soldanelloides Pax, Denticulata Watt, Armerina Lindley, and Aleuritia Duby are resolved as para‐ or polyphyletic with moderate to strong support. Throughout, we consider the striking morphological and cytological variation seen in Primula within a phylogenetic context, particularly as it relates to the close relationship implied here between Dionysia and Primula subgenus Sphondylia. The homology of involute leaf vernation in Primula is reconsidered in light of its two independent origins, and we come to the conclusion that vernation in subgenus Sphondylia is better characterized as conduplicate.