Polygonatum praecox (Asparagaceae), a new species from mid-eastern China revealed by morphological and molecular evidence

A new species, Polygonatum praecox Y.F.Hu & J.W.Shao (Asparagaceae), is described and illustrated. This species is similar to P. cyrtonema, P. odoratum and P. caulialatum, but can be distinguished from P. cyrtonema by its racemose inflorescence, cylindrical hairless filaments and apex without a retrorse spur; from P. odoratum by its stout moniliform rhizome, straight stem and longer (1.7–2.2 cm long) floral tube; and from P. caulialatum by its upper part straight stem, yellowish-green corolla, lobes excurved and earlier flowering. The complete chloroplast genome of this new species is 155,115–155,256 bp in length. Phylogenetic analysis revealed that P. praecox is not genetically related to the above three morphological similar species, but is closely related to the two European species (P. multiforum and P. latifolium). This species is relatively common in mid-eastern China and has previously been confused with P. cyrtonema. As its wild resources have decreased in recent years due to over-exploitation for medicinal or edible purposes, we classify it as Near Threatened (NT) according to the IUCN Red List Criteria.