The following blog was written by Becky Camfield a digitiser in the Herbarium.

Since 2021 we have increased our digitisation capacity reaching 1 million specimens imaged in August 2024. Each digitiser is assigned a family of plants to work through. This series of blogs will spotlight the families that have been completed by a member of the team.

The sweet spire family is found in Eastern America, Mexico, Southern Africa and Eastern Asia. It has a good fossil record and its distribution today suggests it was more widespread in the past. It consists of two genera; Itea and Pterostemon. Itea has 20 species, mostly from Asia apart from 1 species in Africa (Itea rhamnoides) and 1 in America (Itea virginica). Pterostemon has 3 species and is native to Mexico.

They are grown as garden plants due to their pendulous and scented inflorescences.

Our Collections

Before digitisation we had 123  specimens databased. Following digitisation we have 292 specimens available through our online catalogue, of which 10 are type specimens. Our collections can be viewed here.

We have only 2 specimens for Pterostemon and 290 for Itea, although we still have Choristylis (16 specimens), which has been synonymised with Itea. Our representation of Pterostemon is poor as both of our specimens are of P. mexicanus, we have none of the other two species. In Itea the top 3 species are I. chinensis (73), I. macrophylla (43) and I. yunnanensis (39). They account for most of our collections. The other 17 species are underrepresented with I.indochinensis, I. kwangsiensis and I. yangchunensis having no specimens.

Top 5 regions