Erythranthe hallii
Phytoneuron 2012-39: 43. 2012.
Annuals, fibrous-rooted, sometimes apparently rooting at proximal nodes if stems proximally decumbent. Stems erect, simple, 4-angled, 2–8 cm, slender, glabrous. Leaves basal and cauline or basal deciduous, largest at mid-stem or above, cauline relatively few on long internodes; petiole: basal and proximals to midcauline 1–4 mm, distals 0 mm; blade palmately 3-veined, ovate to ovatelanceolate, 5–11 × 3–9 mm, base truncate to cuneate, margins very shallowly dentate or denticulate, apex acute to obtuse, surfaces glabrous or distals and bracteals sparsely villous, hairs vitreous, flattened, eglandular, multicellular. Flowers plesiogamous, (1–) 4–10, sometimes from all nodes, usually beginning about mid-stem, cleistogamous. Fruiting pedicels usually deflexed 90º at calyx, 6–14 mm, longer than subtending leaves. Fruiting calyces sometimes red-dotted, broadly elliptic-ovoid, inflated, sagittally compressed, (5–) 7–10 mm, glabrous, throat closing, adaxial lobe not distinctly longer than abaxial, not falcate. Corollas yellow, usually red-dotted, bilaterally or nearly radially symmetric, bilabiate or nearly regular; tube-throat narrowly cylindric, 4–6 mm, exserted 0.5–1 mm beyond calyx margin; limb barely expanded. Styles glabrous. Anthers included, glabrous. Capsules included, 4–6 mm. 2n = 32.
Phenology: Flowering May–Aug.
Habitat: Ledges, seeps, along streams, wet meadows.
Elevation: 1900–3200 m.
Discussion
Erythranthe hallii is known from Boulder, Clear Creek, Fremont, Grand, Jefferson, Larimer, Routt, and Saguache counties. The Colorado population system is morphologically and geographically coherent.
Erythranthe hallii is similar to E. arvensis; both have four-angled stems, autogamous reproduction, a tendency to root at basal nodes and distally, and both have bracteal leaves villous with vitreous, flattened, eglandular, multicellular hairs, although this vestiture is barely developed and often absent in E. hallii. The only reported chromosome number from the Colorado plants (2n = 32) also appears to be distinct among possible relatives of E. hallii.
Selected References
None.