P. rupestris Balf.f. & Farrer
Section Auganthus
Link to Flora of China description
Type specimen: cult. from seeds of Farrer 734 resides at E (specimen E00024352) and K (specimen K000750117).
Epithet: Named for growing on rocky cliffs.
Distribution: S Shaanxi, N Sichuan, China.
Similar to P. praenitens (P. sinensis), and was first thought to be that species by the collector Farrer. Genetic analysis has confirmed that they are close but distinct. It can be distinguished from P. praenitens by having stout branching rhizomes, thin petioles, few (to five) calyx teeth and a longer corolla tube in relation to the calyx. Though Farrer made a wild collection no. 734, the type is a cultivated plant grown from seeds of collection 734 at Edinburgh. This species is efarinose, glandular hairy with a thick rhizome covered in leaf scars and old leaves. Leaves, sparsely pilose, ovate-rotund, rounded at the apex, truncate or cordate at the base, 5-9 lobed cut to approximately 1/3 with lobes oblong to rotund and margin almost entire to crenate-dentate. Scape 4-15cm glandular pubescent usually with a single umbel of rose, pale lilac or white exannulate flowers with a yellowish-green eye (sometimes a second umbel of 2-3 flowers). P. calciphila, often cited as a synonym, may be distinct.
