Phytoneuron 2012-39: 35. 2012.
Perennials, rhizomatous, densely cespitose, forming large patches and turfs 0.3–1 m diam. Stems erect to ascending, simple, 2–10 cm, sparsely hirsute and stipitate-glandular, internodes shortened. Leaves basal or near basal, sometimes proximal cauline, subrosulate; petiole 0 mm; blade 1-veined or palmately 3-veined, linear to narrowly oblanceolate, 15–50 × 1.5–5 mm, base long-cuneate, often subclasping, margins entire, dentate-serrate, or distally dentate, apex acute, surfaces glabrous or adaxial sparsely short-pilose, eglandular. Flowers herkogamous, 1. Fruiting pedicels (40–) 65–85 (–120) mm, glabrous or sparsely stipitate-glandular near base. Fruiting calyces winged or plicate-angled, tubular-campanulate, weakly or not inflated, 9–10 (–12) mm, glabrous. Corollas yellow, red-spotted or striped, bilaterally symmetric, weakly bilabiate, loosely hirsute on abaxial side of opening; tube-throat narrowly campanulate, 18–22 mm, exserted beyond calyx margin; lobes broadly obovate-oblong, apex rounded or truncate-notched, throat open. Styles glabrous. Anthers included or slightly exserted, margins ciliate, glabrous. Capsules included, 6–7 mm.
Phenology: Flowering Jul–Sep.
Habitat: Wet banks, Darlingtonia seeps and bogs, seepages in serpentine talus.
Elevation: 600–2800 m.
Erythranthe linearifolia is endemic to serpentine substrates in Shasta, Siskiyou, and Trinity counties; typical E. primuloides occurs in the same area but not on serpentine. Erythranthe linearifolia is distinct from E. primuloides especially in its narrow leaves and cespitose habit. A collection from Tulare County appears to be E. linearifolia (Shevock 10597, CAS), but this appears to be far out of range and the voucher should be reexamined; it probably is better identified as an unusual collection of E. primuloides.
"shortened" is not a number.