FNA: Erythranthe exigua vs. Erythranthe willisii

	Erythranthe exigua	Erythranthe willisii
	eye strain monkeyflower, San Bernardino Mountains monkeyflower	Willis' monkeyflower
Habit	Annuals, taprooted.	Perennials, rhizomatous, rarely rooting at proximal nodes, usually forming large colonies, rhizomes white, usually highly branching.
Stems	erect, simple, sometimes branched near base, 2–10 cm, minutely stipitate-glandular.	usually sprawling-decumbent, branched, sometimes simple, 7–45 cm, nodes (2–)4–15+, densely glandular-villous, hairs 1–2 mm, glandular, internodes evident.
Leaves	cauline; petiole 0 mm; blade 1-veined, obovate-oblong to narrowly elliptic, ovate, or narrowly ovate, 3–6 mm, base rounded to truncate or cuneate, margins entire or shallowly dentate, apex rounded, surfaces minutely stipitate-glandular.	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	plesiogamous, (1 or)2–6, from distal or medial to distal nodes.	herkogamous, (4–)8–30+, from medial to distal nodes, sometimes from all nodes.
Styles	glabrous.	glabrous.
Corollas	light lavender to purple, abaxial lobe and palate ridges with yellow patches, bilaterally symmetric, ± bilabiate; tube-throat narrowly funnelform-cylindric, 1.5–2.5 mm, exserted 0.5 mm beyond calyx margin; lobes spreading.	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	divergent-spreading, 15–20 mm, minutely stipitate-glandular.	4–20(–25) mm, densely glandular-villous, hairs 1–2 mm, gland-tipped.
Fruiting calyces	campanulate, 2–2.5 mm, minutely stipitate-glandular.	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	distinctly exserted, 3–4 mm.	included, 4–5 mm.
Stigmas	persistent in fruit.
Anthers	included, glabrous.	included, glabrous or finely hirtellous to scabrous.

	Erythranthe exigua	Erythranthe willisii
Phenology	Flowering Jun–Jul.	Flowering May–Sep.
Habitat	Gentle slopes, along small streams, vernal creeks, pebble plains, openings in Jeffrey pine-juniper forests, runoff areas, vernal depressions, roadsides.	Seepage, drainage margins, moist soils, talus, cracks and crevices, soils deprived from serpentine.
Elevation	1800–2400(–2600) m. (5900–7900(–8500) ft.)	(500–)700–900 m. ((1600–)2300–3000 ft.)
Distribution	CA; Mexico (Baja California) [WildflowerSearch map]	CA
Discussion	Plants of Erythranthe exigua are diminutive annuals with few nodes and greatly reduced leaves, corollas, and calyces, wide spreading pedicels, and lavender flowers with small but bilabiate limbs. The species is known only from the San Bernardino Mountains of San Bernardino County and in adjacent Mexico. (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. 406.	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. 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. 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 exiguus
Name authority	(A. Gray) G. L. Nesom & N. S. Fraga: Phytoneuron 2012-39: 42. (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

eye strain monkeyflower, San Bernardino Mountains monkeyflower

Willis' monkeyflower

Habit

Annuals, taprooted.

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

Stems

erect, simple, sometimes branched near base, 2–10 cm, minutely stipitate-glandular.

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

Leaves

cauline;

petiole 0 mm;

blade 1-veined, obovate-oblong to narrowly elliptic, ovate, or narrowly ovate, 3–6 mm, base rounded to truncate or cuneate, margins entire or shallowly dentate, apex rounded, surfaces minutely stipitate-glandular.

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

plesiogamous, (1 or)2–6, from distal or medial to distal nodes.

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

Styles

glabrous.

Corollas

light lavender to purple, abaxial lobe and palate ridges with yellow patches, bilaterally symmetric, ± bilabiate;

tube-throat narrowly funnelform-cylindric, 1.5–2.5 mm, exserted 0.5 mm beyond calyx margin;

lobes spreading.

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

divergent-spreading, 15–20 mm, minutely stipitate-glandular.

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

Fruiting calyces

campanulate, 2–2.5 mm, minutely stipitate-glandular.

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

distinctly exserted, 3–4 mm.

included, 4–5 mm.

Stigmas

persistent in fruit.

Anthers

included, glabrous.

included, glabrous or finely hirtellous to scabrous.

Erythranthe exigua

Erythranthe willisii

Phenology

Flowering Jun–Jul.

Flowering May–Sep.

Habitat

Gentle slopes, along small streams, vernal creeks, pebble plains, openings in Jeffrey pine-juniper forests, runoff areas, vernal depressions, roadsides.

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

Elevation

1800–2400(–2600) m. (5900–7900(–8500) ft.)

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

Distribution

CA; Mexico (Baja California)

[WildflowerSearch map]

Discussion

Plants of Erythranthe exigua are diminutive annuals with few nodes and greatly reduced leaves, corollas, and calyces, wide spreading pedicels, and lavender flowers with small but bilabiate limbs. The species is known only from the San Bernardino Mountains of San Bernardino County and in adjacent Mexico.

(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. 406.

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. 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. 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 exiguus

Name authority

(A. Gray) G. L. Nesom & N. S. Fraga: Phytoneuron 2012-39: 42. (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 exigua

Erythranthe willisii

Erythranthe exigua

Erythranthe willisii