FNA: Erythranthe linearifolia vs. Erythranthe willisii

	Erythranthe linearifolia	Erythranthe willisii
	primrose monkeyflower, threadleaf primrose monkeyflower	Willis' monkeyflower
Habit	Perennials, rhizomatous, densely cespitose, forming large patches and turfs 0.3–1 m diam.	Perennials, rhizomatous, rarely rooting at proximal nodes, usually forming large colonies, rhizomes white, usually highly branching.
Stems	erect to ascending, simple, 2–10 cm, sparsely hirsute and stipitate-glandular, 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	basal or near basal, sometimes proximal cauline, subrosulate; petiole 0 mm; blade 1-veined or palmately 3-veined, linear to narrowly oblanceolate, 15–50 × 1.5–5 mm, base long-cuneate, often subclasping, margins entire, dentate-serrate, or distally dentate, apex acute, surfaces glabrous or adaxial sparsely short-pilose, 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, red-spotted or -striped, bilaterally symmetric, weakly bilabiate, loosely hirsute on abaxial side of opening; tube-throat narrowly campanulate, 18–22 mm, exserted beyond calyx margin; lobes broadly obovate-oblong, apex rounded- or truncate-notched, throat open.	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	(40–)65–85(–120) mm, glabrous or sparsely stipitate-glandular near base.	4–20(–25) mm, densely glandular-villous, hairs 1–2 mm, gland-tipped.
Fruiting calyces	winged- or plicate-angled, tubular-campanulate, weakly or not inflated, 9–10(–12) 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	included or slightly exserted, margins ciliate, glabrous.	included, glabrous or finely hirtellous to scabrous.

	Erythranthe linearifolia	Erythranthe willisii
Phenology	Flowering Jul–Sep.	Flowering May–Sep.
Habitat	Wet banks, Darlingtonia seeps and bogs, seepages in serpentine talus.	Seepage, drainage margins, moist soils, talus, cracks and crevices, soils deprived from serpentine.
Elevation	600–2800 m. (2000–9200 ft.)	(500–)700–900 m. ((1600–)2300–3000 ft.)
Distribution	CA [WildflowerSearch map]	CA
Discussion	Erythranthe linearifolia is endemic to serpentine substrates in Shasta, Siskiyou, and Trinity counties; typical E. primuloides occurs in the same area but not on serpentine. Erythranthe linearifolia is distinct from E. primuloides especially in its narrow leaves and cespitose habit. A collection from Tulare County appears to be E. linearifolia (Shevock 10597, CAS), but this appears to be far out of range and the voucher should be reexamined; it probably is better identified as an unusual collection of E. primuloides. (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. 390.	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. 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. 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 var. linearifolius, M. linearifolius, M. primuloides subsp. linearifolius
Name authority	(A. L. Grant) 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 Local Web sites: CalFlora, CalPhotos 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 monkeyflower, threadleaf primrose monkeyflower

Willis' monkeyflower

Habit

Perennials, rhizomatous, densely cespitose, forming large patches and turfs 0.3–1 m diam.

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

Stems

erect to ascending, simple, 2–10 cm, sparsely hirsute and stipitate-glandular, 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

basal or near basal, sometimes proximal cauline, subrosulate;

petiole 0 mm;

blade 1-veined or palmately 3-veined, linear to narrowly oblanceolate, 15–50 × 1.5–5 mm, base long-cuneate, often subclasping, margins entire, dentate-serrate, or distally dentate, apex acute, surfaces glabrous or adaxial sparsely short-pilose, 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, red-spotted or -striped, bilaterally symmetric, weakly bilabiate, loosely hirsute on abaxial side of opening;

tube-throat narrowly campanulate, 18–22 mm, exserted beyond calyx margin;

lobes broadly obovate-oblong, apex rounded- or truncate-notched, throat open.

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

(40–)65–85(–120) mm, glabrous or sparsely stipitate-glandular near base.

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

Fruiting calyces

winged- or plicate-angled, tubular-campanulate, weakly or not inflated, 9–10(–12) 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

included or slightly exserted, margins ciliate, glabrous.

included, glabrous or finely hirtellous to scabrous.

Erythranthe linearifolia

Erythranthe willisii

Phenology

Flowering Jul–Sep.

Flowering May–Sep.

Habitat

Wet banks, Darlingtonia seeps and bogs, seepages in serpentine talus.

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

Elevation

600–2800 m. (2000–9200 ft.)

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

Distribution

[WildflowerSearch map]

Discussion

Erythranthe linearifolia is endemic to serpentine substrates in Shasta, Siskiyou, and Trinity counties; typical E. primuloides occurs in the same area but not on serpentine. Erythranthe linearifolia is distinct from E. primuloides especially in its narrow leaves and cespitose habit. A collection from Tulare County appears to be E. linearifolia (Shevock 10597, CAS), but this appears to be far out of range and the voucher should be reexamined; it probably is better identified as an unusual collection of E. primuloides.

(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. 390.

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. 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. 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 var. linearifolius, M. linearifolius, M. primuloides subsp. linearifolius

Name authority

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

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

Web links

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

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Erythranthe linearifolia

Erythranthe willisii

Erythranthe linearifolia

Erythranthe willisii