Common lilac (Syringa vulgaris L.) is a popular landscaping plant. Our aim was to obtain a large set of single nucleotide polymorphism (SNP) markers, to reveal the precise identities of the investigated S. vulgaris accessions, and to discover genetic relationships among them. The studied plant material included local Finnish, previously unidentified accessions, known reference cultivars, and so-called historical accessions i.e., old shrubs growing in historic cultural landscapes. We intended to verify cultivar names for some valuable local common lilac accessions and to provide insights into the history of common lilac cultivation in Finland. In the analyses, we used a set of 15,007 SNP markers. First, polymorphic information contents were calculated (mean 0.190, range 0.012–0.500 per marker). Then, to investigate genetic relationships among genotypes, a phylogenetic tree was constructed, and a principal coordinate analysis was conducted. A Bayesian analysis of population structure was performed to determine the number and distribution of genetic clusters among samples. Genetic marker data combined with existing historical and phenotypic knowledge revealed novel information on the unidentified cultivars and on the genetic relationships among studied accessions and solved the arrival and early history of common lilac in Finland. Overall, such comprehensive genomic characterization and deep understanding of genetic relationships of S. vulgaris can be used when utilizing present cultivars and developing new ones in future breeding programs.

In 1936 the author, politician and garden designer Harold Nicolson bought four, round antique altars and a Corinthian capital from the sale of Shanganagh Castle, Co Wicklow. Nicolson and his wife, Vita Sackville-West, placed these marbles in a garden compartment at Sissinghurst that was intended to evoke the landscape and antiquities of the Cycladic island of Delos. These are among the most important antiquities in the collections of the National Trust, yet their provenance and significance has been obscured by their presumed status as ‘mere’ ornaments to the celebrated gardens at Sissinghurst Castle. This paper traces the provenance of this group of antiquities back to Delos and their discovery by a hero of the Greek War of Independence. Historic context for Vita and Harold’s use of the altars as adornments to their garden will be examined in the context of earlier use of similar Delian altars in earlier garden design – the seventeenth-century ‘garden museum’ at Arundel House, Strand, London, or the eighteenth-century gardens at Wrest Park. Finally, entry of the Sissinghurst altars into British collections will be examined through a political lens and through Nicolson’s philhellenism.