Erythranthe geniculata
Phytoneuron 2012-39: 38. 2012.
Annuals, fibrous-rooted or filiform-taprooted. Stems ascending to decumbent or prostrate, geniculate at nodes, simple or diffusely branched, 5–60 cm, moderately villous, hairs 0.8–2 mm, multicellular, eglandular and also 0.1–0.3 mm, stipitate-glandular. Leaves basal and cauline, basal usually deciduous by flowering; petiole 2–10 (–35) mm; blade pinnately to subpinnately veined, broadly ovate or elliptic-ovate to triangular, 8–35 × 5–30 mm, base cuneate to rounded or subcordate, margins serrate or dentate, teeth 3–10 per side, apex acute to obtuse or rounded, surfaces moderately villous, hairs 0.8–2 mm, multicellular, eglandular, and 0.1–0.3 mm, stipitate-glandular. Flowers herkogamous, (1–) 6–20, from all or medial to distal nodes. Fruiting pedicels 12–26 (–55) mm, moderately villous, hairs 0.8–2 mm, multicellular, eglandular and also 0.1–0.3 mm, stipitate-glandular. Fruiting calyces red-spotted, campanulate-cylindric, weakly inflated, (5–) 6–8 mm, margins distinctly toothed or lobed, sparsely to moderately villous-glandular, ribs shallowly wing-angled, lobes pronounced, erect to spreading or spreading-recurving. Corollas yellow, without white patches, throat red-spotted, spots concentrated or becoming coalescent into a somewhat discrete splotch at base of each of 3 abaxial lobes and sometimes 2 adaxial, bilaterally symmetric, ± bilabiate; tube-throat cylindric, 9–12 mm, exserted beyond calyx margin; limb expanded 10–18 mm diam. Styles glabrous. Anthers included, glabrous. Capsules included, 4–6 (–7) mm. 2n = 32.
Phenology: Flowering (Mar–)Apr–Jul.
Habitat: Granite crevices, canyon slopes, talus, crevices in volcanic outcrops, edges of boulders, roadsides, damp sandy soils, sandy water edges, gravelly soils and creek bottoms.
Elevation: 200–900(–1200) m.
Discussion
Erythranthe geniculata is known from an apparently disjunct cluster of populations in Butte, Sutter, and Yuba counties and then from Tuolumne and Stanislaus counties south to Kern County.
Erythranthe geniculata, compared to E. floribunda, has larger, chasmogamous, and allogamous flowers. The anther pairs of E. geniculata are at different levels, and the stigma is slightly above the adaxial anther pair; in E. floribunda both anther pairs and the stigma are at the same level.
Erythranthe arenaria, E. geniculata, and E. norrisii constitute a group of apparently closely related species within sect. Mimulosma endemic along the Sierra Nevada. All have ovate-petiolate leaves (only the basal ones are sometimes ovate in E. arenaria) with pinnate to subpinnate venation. The more widespread E. floribunda, which is part of the above group, also is similar, but all three endemics have larger corollas with the tube exserted at greater length beyond the calyx margin.
Selected References
None.