Section Auganthus photographs

Section Auganthus (Link) Pax ex Balf.f., J. Roy. Hort. Soc. 39:139. 1913.

Type species: P. praenitens Ker Gawl. (P. sinensis Sabine)

P. filchnerae
P. hubeiensis
P. praenitens
--- P. sinensis (nom. illeg.)
--- Primulidium sinense (nom. illeg.)
--- Auganthus praenitens
--- P. mandarina
--- P. semperflorens
--- P. sertulosa
P. rupestris
--- P. calciphila

Distinguished by the inflated calyx with a flat base. Leaves pilose, glandular, without farina, pinnatisect, with a distinct petiole. Flowers red to white, heterostylous. Capsule globose, opening by valves.
P. filchnerae is the type species for section Pinnatae R.Knuth, and it is morphologically similar to other species in that section, but more recent analysis places it in section Auganthus. P. praenitens is well known under the name P. sinensis, but that name is illegitimate. See an explanation of this. P. rupestris is nearly indistinguishable from P. praenitens and is has been thought it to be a wild progenitor for the cultivated P. praenitens. However genetic studies indicate they are separate species and attempts to hybridize the two species have failed. The recently described species P. hubeiensis is provisionally placed in this section.
See Circumscriptions and phylogenetic relationships of Primula sects. Auganthus and Ranunculoides: Evidence from nrDNA ITS sequences" Hao, Hu & Lee. 2002 (PDF).