Subshrubs or shrubs. Stems erect to ascending-erect or sprawling, 200–1500(–2000) mm, glabrous. Leaves cauline, relatively even-sized; petiole absent; blade linear-oblong or narrowly elliptic to narrowly lanceolate or oblanceolate, 10–60 × 1–11(–15) mm, margins entire or serrate, plane or revolute, apex acute, surfaces glabrous. Pedicels 5–25 mm in fruit. Flowers 2(–4) per node, chasmogamous. Calyces not inflated in fruit, 17–25 mm, glabrous, lobes unequal, apex acute, ribs green, intercostal areas light green. Corollas deep red, orange-red, or orange to maroon, throat sometimes orangish, palate ridges red, rarely yellow, tube-throat 27–35 mm, limb 15–23 mm diam., bilabiate, lobes oblong, apex truncate, sometimes notched. Anthers (distal pair) exserted, glabrous. Styles minutely glandular. Stigmas exserted, lobes equal. Capsules 14–22 mm. 2n = 20.
Phenology: Flowering Jan–Jul(–Oct).
Habitat: Rocky hillsides, boulders, moist hillsides, canyons, wash bottoms, roadsides, chaparral.
Elevation: (20–)100–700 m.
Calif., Mexico (Baja California).
Diplacus puniceus occurs in southwestern California and northeastern Baja California. Hybrids are common with D. longiflorus and have been called D. ×australis.