Erythranthe regni

Annuals, fibrous-rooted, sometimes rooting at proximal nodes. Stems erect to ascending-erect, branched, sometimes becoming slightly fistulose, 15–45 cm, glabrous. Leaves basal and cauline; petiole: proximals 5–25 (–30) mm, mid cauline and distals not connate, 0 mm; blade palmately 5–7-veined, proximal sometimes subpinnate, proximals ovate to depressed-orbicular, 15–20 (–50) × 15–25 (–50) mm, medials and distals broadly depressed-ovate to obtriangular or flabellate, 15–35 mm, largest basal or at mid-stem with distal slightly reduced, base attenuate-cuneate, margins shallowly serrate-dentate, sometimes irregularly, to mucronulate or apiculate, teeth (3–) 5–7 per side, rarely subentire, apex rounded, surfaces glabrous. Flowers plesiogamous, 6–16, from all nodes or medial to distal, cleistogamous. Fruiting pedicels 15–30 mm, longer than subtending leaves, glabrous. Fruiting calyces sparsely purple-dotted, broadly campanulate-cylindric, inflated, sagittally compressed, 7–9 mm, glabrous, throat not closing, adaxial lobe longest. Corollas yellow, not red-dotted, bilaterally or radially symmetric, bilabiate or regular; tube-throat cylindric-funnelform, 9–12 mm, exserted 3–5 mm beyond calyx margin; limb expanded 1–1.5 mm. Styles glabrous. Anthers included, glabrous. Capsules included, 4–5 mm.

Phenology: Flowering Mar–May.
Habitat: Moist to wet, sandy loam soils.
Elevation: 800–1000 m.

Ariz.

Discussion

Erythranthe regni is endemic to the Kofa Mountains of Yuma County; all collections have been made from the Kofa Game Refuge (Kofa National Wildlife Refuge). Because its calyces remain open at maturity, this species is hypothesized to be most closely related to E. geyeri, from which it differs by its erect habit, apparently annual duration, larger leaves, purple-dotted calyces, and corollas with longer tube-throat and barely bilabiate limb. Geography and other morphology, however, suggest that its evolutionary origins are closer to E. guttata.

Selected References

None.

Lower Taxa