Crataegus x lavalleei has a specific origin story, unusual for a hawthorn: it appeared as a seedling at the Arboretum Segrez in France, a chance cross between two hawthorn species that was later developed and named by Pierre Alphonse Martin Lavallée, the 19th-century botanist and horticulturist who owned the estate from 1856. That deliberate refinement shows. The tree grows 15 to 30 feet tall with a dense, rounded to slightly irregular form, more erect and closely branched than most hawthorns, which gives it a tidier presence in a designed landscape. It can also be managed as a multi-stemmed large shrub where a tree silhouette is not wanted.

The white spring flowers come in clusters and carry what is generously called a fragrance and less charitably an odor — placing this tree away from windows and seating areas is practical advice rather than an insult. The fall and winter show is where it earns its keep: orange-red berries that persist long after the leaves have fallen, coloring the bare framework of the crown through the coldest months. It tolerates most well-drained soils, is drought-tolerant once established, and shows better resistance to rusts and fireblight than many hawthorns. The two-inch thorns make it unsuitable along paths, but as a barrier hedge or winter-interest specimen, it is a considered choice.