Solidago durangensis

Solidago durangensis Nesom is a little known species from Durango, Mexico.  In the protogue, Nesom (1991) compared the species to S. missouriensis, but rejected a close relationship favoring possible relationships with members of subsect. Maritimae (S. paniculata, S. virgata as S. stricta) or S. confinis, which is related to S. missouriensis.  I at one time thought that S. durangensis was the only really hairy member of subsect. Junceae -- possibly a primitive trait linking the subsection to other subsections in Mexico. Solidago argentinensis is hairier than other species of the subsect. Junceae but still much less so than S. durangensis.  Palmer 217 (F and MO) have fascicles of small leaves in the axes of some upper stem leaves; this is a subsect. Junceae trait.  The number of rays and discs reported by Nesom is similar to the range for S. spectabilis. The stem pubescence is shared by species in subsect. Triplinerviae, subsect. Nemorales, and species in other subsections. The branching pattern of the inflorescence is more like S. juncea and S. missouriensis than members of S. subsect. Triplinerviae.  The very limited old herbarium material available lacks basal portions of the stem. Knowledge of basal leaf traits and petiole traits would help clarify the phylogenetic position. 

To resolve the problem of relationships of S. durangensis, Semple and Lopez Laphitz (2016) included specimens of S. durangensis in a multivariate study that also included specimens of subsect. Junceae, subsect. Maritimae, and subsect. Triplinerviae.  The two specimens of S. durangensis were included in the a posteriori classification analysis and were placed in the S. pringlei or S. chilensis group.  Thus, it was concluded that S. durangensis belongs in subsect. Triplinerviae in the informal Tortifoliae group including southern U.S., Mexican and South American species.

The chromosome number is unknown.