In 1907 Sargent published his Crataegus douglasii var. suksdorfii, based on Crataegus collections sent him by Wilhelm Suksdorf. Suksdorf had noted variation in the number of stamens in the black-fruited specimens and Sargent replied that he was surprised to learn of a 10-stamen form with black fruit. Sargent then ascertained that the type of Lindley's C. douglasii (grown from seed collected by David Douglas in the Columbia River basin) in fact corresponded to Suksdorf's 10-stamen form, and named the new 20-stamen variety in Suksdorf's honor. Although Sargent referred to C. punctata var. brevispina Douglas (published by Hooker in 1832) in his treatment of C. douglasii for Sylva of North America (1892) he apparently neglected Hooker's comment that Douglas' specimens comprised two varieties. Moreover, in his 1907 paper he mentioned that Heller had published C. gaylussacia based on black-fruited specimens from California. What then is Sargent's C. suksdorfii? Recent opinion has recognized only Lindley's and Sargent's taxa, contrasting them on the basis of correlated variation in leaf shape, thorn size, and floral architecture. In seeking to understand the variation in floral architecture within these black-fruited hawthorns I have attempted to resolve what names should be applied to what phenotypes. Suksdorf provided collections of southern Washington plants to many herbaria, so that there are several specimens available from the individuals referred to in the protologue for var. suksdorfii. Leaf, thorn, and floral measurements, including Fourier analyses of leaf outlines, reveal that this type material is distinct from both varieties collected by Douglas, leading to a proposal for restricting the application of Sargent's name, and resurrecting one or both of the names proposed by Douglas and Heller to account for the phenotypes associated with C. suksdorfii up to now.

Key words: Crataegus suksdorfii, Fourier, hawthorn, Suksdorf, typification