The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

little redstem monkeyflower, red stem himulus, redstem monkeyflower, redstem or little redstem monkeyflower

field monkey-flower, villous-bract monkeyflower, western monkey-flower

Habit Annuals, taprooted. Annuals, taprooted or fibrous-rooted, sometimes rooting at proximal cauline nodes if decumbent.
Stems

erect, simple, sometimes branched from basal nodes, 3–32 cm, minutely puberulent.

erect to decumbent-ascending, simple or branched from proximal to medial nodes, usually 4-angled, fistulose to very narrow, 5–70 cm, glabrous, sometimes minutely hirtellous in inflorescence, hairs deflexed, eglandular.

Leaves

cauline, basal not persistent;

petiole 0 mm;

blade palmately 3-veined (in broader ones), linear to elliptic, 5–22(–30) × 1–5 mm, base narrowed, margins entire, sometimes toothed, apex acute to obtuse, surfaces minutely puberulent.

basal and cauline or basal not persistent, often largest at mid stem or above, reduced in size distally;

petiole 3–20(–90) mm, distals 0 mm;

blade palmately 3–5-veined, ovate to orbicular, orbicular-ovate, oblong-ovate, or (middle and distal cauline) broadly orbicular to depressed-ovate or nearly reniform, (5–)10–35(–45) × 6–26(–50) mm, distal closely paired, auriculate-subclasping, base rounded to truncate, subcordate, or shallowly cordate, margins denticulate or subentire to distinctly dentate, on larger plants proximal characteristically lacerate-lobed to pinnatifid at margin base, apex rounded, surfaces glabrous except for bracts densely villous abaxially, sometimes also adaxially, hairs long, sometimes vitreous, flattened, eglandular, multicellular.

Flowers

herkogamous, sometimes plesiogamous, 1–106, from distal or medial to distal nodes.

plesiogamous, 3–8(–16), from remote distal nodes, chasmogamous or cleistogamous.

Styles

glabrous.

glabrous.

Corollas

yellow and abaxial limb and throat red dotted or pink to purple and throat yellow, bilaterally symmetric, weakly bilabiate;

tube-throat cylindric, 4–10 mm, exserted beyond calyx margin;

limb expanded 3–5 mm, lobes entire or weakly notched, abaxial limb glabrous.

yellow, usually red-spotted, weakly bilaterally or nearly radially symmetric, weakly bilabiate or nearly regular;

tube-throat cylindric-funnelform, (7–)8–12 mm, exserted (0–)1–2(–3) mm beyond calyx margin;

limb expanded 5–10 mm.

Fruiting pedicels

2–18 mm.

5–40(–90) mm, longer than subtending leaves, glabrous.

Fruiting calyces

becoming red-angled or red, campanulate to nearly cylindric, 4–9 mm, margins distinctly toothed or lobed, glabrous or minutely puberulent, ribs thickened, lobes pronounced, erect, margins ciliate.

red-dotted or not, ovate-campanulate, inflated, sagittally compressed, (7–)9–14 mm, minutely hirtellous, throat closing or not, remaining open, lobes upcurving weakly, adaxial lobe not distinctly longer than abaxial, not falcate.

Capsules

included, 3–8 mm.

included, stipitate, (5–)6–7 mm.

Anthers

included, glabrous.

included, glabrous.

2n

= 28.

Erythranthe rubella

Erythranthe arvensis

Phenology Flowering Apr–Jun. Flowering Apr–Jun(–Jul).
Habitat Open slopes and washes. Hills, ridges, clay banks, stream banks, moist woods.
Elevation 300–3000 m. [1000–9800 ft.] 30–1900(–2300) m. [100–6200(–7500) ft.]
Distribution
from FNA
AZ; CA; CO; NM; NV; TX; UT; WY; Mexico (Baja California, Sonora)
[WildflowerSearch map]
from FNA
CA; ID; MT; NV; OR; UT; WA; WY; BC; Mexico (Baja California)
[WildflowerSearch map]
Discussion

Erythranthe arvensis usually is easily recognized, characterized by its annual duration (but commonly rooting at proximal cauline nodes, suggestive of a rhizomatous habit), glabrous stems with nodes relatively few and remotely spaced, depressed-ovate leaves with margins often sublyrate (lacerate-lobed to subpinnatifid) at the base, distal leaves and bracts densely villous with vitreous eglandular hairs, other leaves glabrous, and corollas varying in size from relatively small but perhaps chasmogamous (the type of Mimulus arvensis) to even smaller (cleistogamous; the type of M. micranthus). The breeding system is consistently autogamous. The relatively short and even-sized calyx lobes that do not turn upward to close the orifice have been considered diagnostic of E. arvensis. This feature is evident in some plants, but others (perhaps reflecting gene flow from other species) have a longer adaxial calyx lobe and abaxial lobes that turn upward variably.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 17, p. 384. Treatment authors: Guy L. Nesom, Naomi S. Fraga. FNA vol. 17, p. 420. Treatment authors: Guy L. Nesom, Naomi S. Fraga.
Parent taxa Phrymaceae > Erythranthe Phrymaceae > Erythranthe
Sibling taxa
E. acutidens, E. alsinoides, E. ampliata, E. androsacea, E. arenaria, E. arenicola, E. arvensis, E. barbata, E. bicolor, E. brachystylis, E. breviflora, E. breweri, E. caespitosa, E. calcicola, E. calciphila, E. cardinalis, E. carsonensis, E. charlestonensis, E. chinatiensis, E. cinnabarina, E. corallina, E. cordata, E. decora, E. dentata, E. diffusa, E. discolor, E. eastwoodiae, E. erubescens, E. exigua, E. filicaulis, E. filicifolia, E. floribunda, E. gemmipara, E. geniculata, E. geyeri, E. glaucescens, E. gracilipes, E. grandis, E. grayi, E. guttata, E. hallii, E. hardhamiae, E. hymenophylla, E. inamoena, E. inconspicua, E. inflatula, E. jungermannioides, E. laciniata, E. latidens, E. lewisii, E. linearifolia, E. marmorata, E. michiganensis, E. microphylla, E. minor, E. montioides, E. moschata, E. nasuta, E. norrisii, E. nudata, E. palmeri, E. pardalis, E. parishii, E. parvula, E. patula, E. percaulis, E. primuloides, E. ptilota, E. pulsiferae, E. purpurea, E. regni, E. rhodopetra, E. scouleri, E. shevockii, E. sierrae, E. suksdorfii, E. taylorii, E. thermalis, E. tilingii, E. trinitiensis, E. unimaculata, E. utahensis, E. verbenacea, E. washingtonensis, E. willisii, E. veronicifolia
E. acutidens, E. alsinoides, E. ampliata, E. androsacea, E. arenaria, E. arenicola, E. barbata, E. bicolor, E. brachystylis, E. breviflora, E. breweri, E. caespitosa, E. calcicola, E. calciphila, E. cardinalis, E. carsonensis, E. charlestonensis, E. chinatiensis, E. cinnabarina, E. corallina, E. cordata, E. decora, E. dentata, E. diffusa, E. discolor, E. eastwoodiae, E. erubescens, E. exigua, E. filicaulis, E. filicifolia, E. floribunda, E. gemmipara, E. geniculata, E. geyeri, E. glaucescens, E. gracilipes, E. grandis, E. grayi, E. guttata, E. hallii, E. hardhamiae, E. hymenophylla, E. inamoena, E. inconspicua, E. inflatula, E. jungermannioides, E. laciniata, E. latidens, E. lewisii, E. linearifolia, E. marmorata, E. michiganensis, E. microphylla, E. minor, E. montioides, E. moschata, E. nasuta, E. norrisii, E. nudata, E. palmeri, E. pardalis, E. parishii, E. parvula, E. patula, E. percaulis, E. primuloides, E. ptilota, E. pulsiferae, E. purpurea, E. regni, E. rhodopetra, E. rubella, E. scouleri, E. shevockii, E. sierrae, E. suksdorfii, E. taylorii, E. thermalis, E. tilingii, E. trinitiensis, E. unimaculata, E. utahensis, E. verbenacea, E. washingtonensis, E. willisii, E. veronicifolia
Synonyms Mimulus rubellus, M. gratioloides Mimulus arvensis, M. guttatus subsp. arvensis, M. guttatus var. arvensis, M. guttatus subsp. micranthus, M. langsdorffii var. arvensis, M. longulus, M. micranthus
Name authority (A. Gray) N. S. Fraga: Phytoneuron 2012-39: 35. (2012) (Greene) G. L. Nesom: Phytoneuron 2012-39: 43. (2012)
Web links