FNA: Erythranthe primuloides vs. Erythranthe willisii

	Erythranthe primuloides	Erythranthe willisii
	primrose monkey-flower	Willis' monkeyflower
Habit	Perennials, rhizomatous or stoloniferous, mat-forming, rhizomes or stolons flagelliform.	Perennials, rhizomatous, rarely rooting at proximal nodes, usually forming large colonies, rhizomes white, usually highly branching.
Stems	erect to ascending, usually simple, 2–10(–20) cm, villous, internodes shortened.	usually sprawling-decumbent, branched, sometimes simple, 7–45 cm, nodes (2–)4–15+, densely glandular-villous, hairs 1–2 mm, glandular, internodes evident.
Leaves	all basal or near basal, often rosulate; petiole 0 mm; blade palmately 3-veined, oblanceolate to elliptic-obovate, 7–40 × 4–12 mm, base cuneate to attenuate, margins entire, distally denticulate to dentate, or sharply serrate-dentate, apex acute to obtuse, abaxial surface glabrous, adaxial glabrous or glabrate to sparsely to densely long-villous, eglandular.	usually cauline, basal not persistent, distinctly separated; petiole 0 mm, sometimes 1–2 mm at proximal nodes; blade bicolored, purplish abaxially, pinnately veined, ovate to elliptic-ovate, midcauline 10–35 × 6–18 mm, base rounded to subcordate, margins coarsely serrate-dentate to denticulate or subentire, apex short-attenuate to acute, obtuse, or rounded, surfaces densely glandular-villous, hairs 1–2 mm, gland-tipped.
Flowers	herkogamous, 1.	herkogamous, (4–)8–30+, from medial to distal nodes, sometimes from all nodes.
Styles	glabrous.	glabrous.
Corollas	yellow to orange-yellow, usually brown-spotted abaxially, base of each abaxial lobe usually with a larger reddish brown spot, bilaterally or nearly radially symmetric, weakly bilabiate or nearly regular, densely hirsute on abaxial side of opening; tube-throat narrowly campanulate, 15–20 mm, exserted beyond calyx margin; lobes broadly obovate-oblong, apex rounded- or truncate-notched, throat open, palate densely villous, abaxial ridges prominent.	yellow, throat, tube, and proximal portion of abaxial 3 lobes with fine, red to brownish lines, weakly bilaterally or nearly radially symmetric, weakly bilabiate or nearly regular; tube-throat narrowly funnelform, 12–15 mm, exserted beyond calyx margin; limb 9–12 mm wide (pressed), lobes oblong-obovate, apex rounded to notched.
Fruiting pedicels	30–110(–130) mm, glabrous or sparsely stipitate-glandular near base.	4–20(–25) mm, densely glandular-villous, hairs 1–2 mm, gland-tipped.
Fruiting calyces	tubular-campanulate, weakly or not inflated, 6–8 mm, glabrous.	ridge- to wing-angled, campanulate to cylindric-campanulate, weakly inflated, 7–10 mm, densely glandular-villous, lobes erect to slightly spreading, unequal, triangular to linear-lanceolate, 2–4 mm, apex acuminate-apiculate.
Capsules	included, 6–7 mm.	included, 4–5 mm.
Anthers	slightly exserted, margins ciliate, glabrous.	included, glabrous or finely hirtellous to scabrous.
2n	= 34.

	Erythranthe primuloides	Erythranthe willisii
Phenology	Flowering Jun–Aug.	Flowering May–Sep.
Habitat	Wet meadows, seeps, streamsides.	Seepage, drainage margins, moist soils, talus, cracks and crevices, soils deprived from serpentine.
Elevation	600–3400 m. (2000–11200 ft.)	(500–)700–900 m. ((1600–)2300–3000 ft.)
Distribution	AZ; CA; ID; MT; NM; NV; OR; UT; WA [WildflowerSearch map]	CA
Discussion	Flowers in Erythranthe primuloides and E. linearifolia characteristically appear to be scapose, but the scapes are pedicels arising from axils of greatly foreshortened stems. Occasionally in both species the internodes may lengthen somewhat, and the leaves are not so densely clustered at the base of the stems. In northern Klamath, western Deschutes, and eastern Douglas counties, Oregon, an area within the range of typical populations, Erythranthe primuloides has distinctively large corollas (limbs 10–15 mm wide). Apparent clones of large-flowered and smaller-flowered plants sometimes grow in close proximity or even intermixed, appearing as two different entities. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Erythranthe willisii is narrowly endemic over serpentine along the North Fork Feather River (including the North Branch) in Plumas County. In the original description, its range was said to include serpentine localities in closely adjacent areas of east-central Butte, Plumas, and northwestern Yuba counties, but subsequent field work has shown that these peripheral populations are E. moschata, and that E. willisii occurs only in the bottom of the Serpentine Canyon area. The most consistent and recognizable features of E. willisii are the long, sprawling stems often spread over a large area, sometimes reaching at least 45 cm and often with many crowded nodes, sessile or subsessile leaves with rounded to subcordate bases, and short pedicels, characteristically no longer than the subtending leaves (except sometimes the distal ones where subtending leaves are distinctly reduced in size). It is possible that stem growth in E. willisii is indeterminate versus determinate in E. moschata. Sessile to subsessile leaves occur in E. moschata, especially in the California Sierra Nevada, but petiole length and leaf base shape are variable within populations; lack of petioles and a rounded/subcordate base are fixed characters in E. willisii (as they are also in E. ptilota). Although large colonies of E. moschata are sometimes encountered, the individual plants tend to be erect (in California) and with few distal flowers. In the field, the dense vestiture of E. willisii is a prominent feature, but this is harder to distinguish in pressed specimens, and there is a strong tendency for purple abaxial leaf coloration in E. willisii. Phenology and flower morphology of E. willisii and E. moschata appear to be similar, but E. moschata in north-central California does not occur at as low elevations as E. willisii. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 17, p. 389.	FNA vol. 17, p. 401.
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. 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. 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. 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
Synonyms	Mimulus primuloides, M. nevadensis, M. pilosellus, M. primuloides var. minimus, M. primuloides var. pilosellus
Name authority	(Bentham) G. L. Nesom & N. S. Fraga: Phytoneuron 2012-39: 35. (2012)	G. L. Nesom: Phytoneuron 2017-17: 7, figs. 14–22. (2017)
Web links	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Erythranthe willisii

primrose monkey-flower

Willis' monkeyflower

Habit

Perennials, rhizomatous or stoloniferous, mat-forming, rhizomes or stolons flagelliform.

Perennials, rhizomatous, rarely rooting at proximal nodes, usually forming large colonies, rhizomes white, usually highly branching.

Stems

erect to ascending, usually simple, 2–10(–20) cm, villous, internodes shortened.

usually sprawling-decumbent, branched, sometimes simple, 7–45 cm, nodes (2–)4–15+, densely glandular-villous, hairs 1–2 mm, glandular, internodes evident.

Leaves

all basal or near basal, often rosulate;

petiole 0 mm;

blade palmately 3-veined, oblanceolate to elliptic-obovate, 7–40 × 4–12 mm, base cuneate to attenuate, margins entire, distally denticulate to dentate, or sharply serrate-dentate, apex acute to obtuse, abaxial surface glabrous, adaxial glabrous or glabrate to sparsely to densely long-villous, eglandular.

usually cauline, basal not persistent, distinctly separated;

petiole 0 mm, sometimes 1–2 mm at proximal nodes;

blade bicolored, purplish abaxially, pinnately veined, ovate to elliptic-ovate, midcauline 10–35 × 6–18 mm, base rounded to subcordate, margins coarsely serrate-dentate to denticulate or subentire, apex short-attenuate to acute, obtuse, or rounded, surfaces densely glandular-villous, hairs 1–2 mm, gland-tipped.

Flowers

herkogamous, 1.

herkogamous, (4–)8–30+, from medial to distal nodes, sometimes from all nodes.

Styles

glabrous.

Corollas

yellow to orange-yellow, usually brown-spotted abaxially, base of each abaxial lobe usually with a larger reddish brown spot, bilaterally or nearly radially symmetric, weakly bilabiate or nearly regular, densely hirsute on abaxial side of opening;

tube-throat narrowly campanulate, 15–20 mm, exserted beyond calyx margin;

lobes broadly obovate-oblong, apex rounded- or truncate-notched, throat open, palate densely villous, abaxial ridges prominent.

yellow, throat, tube, and proximal portion of abaxial 3 lobes with fine, red to brownish lines, weakly bilaterally or nearly radially symmetric, weakly bilabiate or nearly regular;

tube-throat narrowly funnelform, 12–15 mm, exserted beyond calyx margin;

limb 9–12 mm wide (pressed), lobes oblong-obovate, apex rounded to notched.

Fruiting pedicels

30–110(–130) mm, glabrous or sparsely stipitate-glandular near base.

4–20(–25) mm, densely glandular-villous, hairs 1–2 mm, gland-tipped.

Fruiting calyces

tubular-campanulate, weakly or not inflated, 6–8 mm, glabrous.

ridge- to wing-angled, campanulate to cylindric-campanulate, weakly inflated, 7–10 mm, densely glandular-villous, lobes erect to slightly spreading, unequal, triangular to linear-lanceolate, 2–4 mm, apex acuminate-apiculate.

Capsules

included, 6–7 mm.

included, 4–5 mm.

Anthers

slightly exserted, margins ciliate, glabrous.

included, glabrous or finely hirtellous to scabrous.

= 34.

Erythranthe primuloides

Erythranthe willisii

Phenology

Flowering Jun–Aug.

Flowering May–Sep.

Habitat

Wet meadows, seeps, streamsides.

Seepage, drainage margins, moist soils, talus, cracks and crevices, soils deprived from serpentine.

Elevation

600–3400 m. (2000–11200 ft.)

(500–)700–900 m. ((1600–)2300–3000 ft.)

Distribution

AZ; CA; ID; MT; NM; NV; OR; UT; WA

[WildflowerSearch map]

Discussion

Flowers in Erythranthe primuloides and E. linearifolia characteristically appear to be scapose, but the scapes are pedicels arising from axils of greatly foreshortened stems. Occasionally in both species the internodes may lengthen somewhat, and the leaves are not so densely clustered at the base of the stems.

In northern Klamath, western Deschutes, and eastern Douglas counties, Oregon, an area within the range of typical populations, Erythranthe primuloides has distinctively large corollas (limbs 10–15 mm wide). Apparent clones of large-flowered and smaller-flowered plants sometimes grow in close proximity or even intermixed, appearing as two different entities.

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

Erythranthe willisii is narrowly endemic over serpentine along the North Fork Feather River (including the North Branch) in Plumas County. In the original description, its range was said to include serpentine localities in closely adjacent areas of east-central Butte, Plumas, and northwestern Yuba counties, but subsequent field work has shown that these peripheral populations are E. moschata, and that E. willisii occurs only in the bottom of the Serpentine Canyon area. The most consistent and recognizable features of E. willisii are the long, sprawling stems often spread over a large area, sometimes reaching at least 45 cm and often with many crowded nodes, sessile or subsessile leaves with rounded to subcordate bases, and short pedicels, characteristically no longer than the subtending leaves (except sometimes the distal ones where subtending leaves are distinctly reduced in size). It is possible that stem growth in E. willisii is indeterminate versus determinate in E. moschata. Sessile to subsessile leaves occur in E. moschata, especially in the California Sierra Nevada, but petiole length and leaf base shape are variable within populations; lack of petioles and a rounded/subcordate base are fixed characters in E. willisii (as they are also in E. ptilota). Although large colonies of E. moschata are sometimes encountered, the individual plants tend to be erect (in California) and with few distal flowers. In the field, the dense vestiture of E. willisii is a prominent feature, but this is harder to distinguish in pressed specimens, and there is a strong tendency for purple abaxial leaf coloration in E. willisii. Phenology and flower morphology of E. willisii and E. moschata appear to be similar, but E. moschata in north-central California does not occur at as low elevations as E. willisii.

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

Source

FNA vol. 17, p. 389.

FNA vol. 17, p. 401.

Parent taxa

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. 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. 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. 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

Synonyms

Mimulus primuloides, M. nevadensis, M. pilosellus, M. primuloides var. minimus, M. primuloides var. pilosellus

Name authority

(Bentham) G. L. Nesom & N. S. Fraga: Phytoneuron 2012-39: 35. (2012)

G. L. Nesom: Phytoneuron 2017-17: 7, figs. 14–22. (2017)

Web links

Local floras: CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria
WildflowerSearch
iNaturalist (observations)
LBJ Wildflower Center
SEINet
Plants of the World Online
Encyclopedia of Life
Wikipedia
Google Image Search

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:

Flora of North America species comparison

Erythranthe primuloides

Erythranthe willisii

Erythranthe primuloides

Erythranthe willisii