Pachycarpus galpinii flowers grow in small clusters at stem-tips and from leaf axils near stem-tips. The sturdy, hairy pedicels are curved, allowing the flowers to nod. Flowering happens at least from before midspring to after midsummer.

The fruit is a pair of spindle-shaped follicles, only one of each pair developing in most cases (Leistner, (Ed.), 2000; iNaturalist).