adobe popcornflower

Plagiobothrys acanthocarpus (Piper) I.M.Johnst.

Adobe popcornflower is a modest annual whose most striking structures are easiest to see with magnification. Its slender stems spread or stand upright, usually branching near the base, and reach about 10–40 cm. Short, closely lying hairs cover the herbage, while small leaves accompany the flowering branches. Abrams (1951), Illustrated Flora of the Pacific States: Allocarya acanthocarpa

Botanical name

Plagiobothrys acanthocarpus (Piper) I.M.Johnst. is accepted in Boraginaceae. Allocarya acanthocarpa Piper is its basionym. Kew Plants of the World Online: Plagiobothrys acanthocarpus

Recognizing the plant

Lower leaves are narrow and about 2–6 cm long; upper leaves and floral bracts are smaller and similarly slender. Flower clusters lengthen and loosen as they develop. The corolla is only about 1–2.5 mm across and barely exceeds the calyx. Mature nutlets are egg-shaped, with a network of narrow ridges carrying long, slender, minutely barbed prickles. A sunken attachment scar lies near the base on one side. Abrams (1951), Illustrated Flora of the Pacific States: Allocarya acanthocarpa

Bloom window

California and northern Baja California

Abrams’ Pacific States flora records flowering from March to May in California and northern Baja California. Abrams (1951), Illustrated Flora of the Pacific States: Allocarya acanthocarpa

Native range

The native range runs from central California south into northern Baja California. Regional floras place it in vernal pools, wet ground and clay-rich flats. Kew Plants of the World Online: Plagiobothrys acanthocarpus Abrams (1951), Illustrated Flora of the Pacific States: Allocarya acanthocarpa UC Davis, Plants of the Cosumnes River Preserve: Plagiobothrys acanthocarpus

Botanical sources

Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.