Flora of North America species comparison

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Erythranthe microphylla

Erythranthe cordata

Bentham's monkeyflower, small-leaf monkey-flower

tinytooter monkeyflower
Habit Annuals, fibrous-rooted. Annuals, fibrous-rooted, sometimes producing leafy runners from basal nodes, stems often rooting at proximal nodes and appearing rhizomelike.
Stems

erect, simple, sometimes many-branched from basal cauline nodes, terete, sometimes distinctly 4-angled, (3–)5–30(–45) cm, glabrous below inflorescence, sometimes distals hirtellous, hairs commonly deflexed, or mixed hirtellous and stipitate-glandular, sometimes only short villous-glandular, hairs gland-tipped.

usually erect, usually simple, usually fistulose, 12–40(–100) cm, sparsely stipitate-glandular, hairs fine, gland-tipped.
Leaves

basal and cauline, basal sometimes absent at flowering;

petiole: basal or proximals to medials 3–25(–35) mm, distals 0 mm (then blade subclasping to narrowly perfoliate);

blade often purplish, palmately 3–5-veined, ovate or ovate-lanceolate to elliptic-ovate, suborbicular, or depressed-ovate, (3–)10–35 × 3–25 mm, base rounded to truncate or subcordate, margins shallowly crenate to sharply crenate-serrate, teeth 5–10 per side, basal and proximal often irregularly incised near petiole and sublyrate, apex acute to obtuse-rounded, surfaces glabrous or sparsely to moderately hirtellous, eglandular.

basal and cauline, basal persistent;

petiole: basal and proximals 6–20(–40) mm, midcauline to distals 0 mm;

blade not connate, palmately 3–5(–7)-veined, orbicular to broadly elliptic-ovate or oblong-elliptic, cauline becoming broadly ovate to narrowly reniform, basal and mid cauline 15–30(–50) mm, gradually reduced in size distally to 6 mm, basal largest, distal closely paired, auriculate-subclasping, base cuneate to truncate or shallowly cordate, margins shallowly, evenly to unevenly dentate, apex obtuse to rounded, surfaces glabrous.
Flowers

herkogamous, 1–8(–14), usually from distal nodes, chasmogamous.

plesiogamous, (5–)10–16, at distal nodes, in bracteate racemes, chasmogamous or cleistogamous.
Styles

sparsely hirtellous.

glabrous.
Corollas

yellow to golden yellow or orangish yellow, usually red-spotted, abaxial limb sometimes with a large red splotch, bilaterally symmetric, bilabiate;

tube-throat broadly funnelform, (6–)8–16(–20) mm, exserted (1–)2–6(–8) mm beyond calyx margin;

limb expanded 8–25 mm, palate villous.

yellow, red-spotted, abaxial limb deeper yellow, weakly bilaterally or radially symmetric, weakly bilabiate or regular;

tube-throat sometimes tubular and not opening (cleistogamous), 8–14 mm, exserted 1–3 mm beyond calyx margin;

limb not expanded or expanded 9–14 mm.
Fruiting pedicels

8–30(–50) mm, distals hirtellous, hairs commonly deflexed, or mixed hirtellous and stipitate-glandular, sometimes only short villous-glandular, hairs gland-tipped.

10–30(–45) mm, longer than subtending leaves, minutely stipitate-glandular.
Fruiting calyces

nodding 30–90º, sometimes red-tinged or -dotted, ovoid-campanulate to broadly cylindric-campanulate, inflated, sagittally compressed, (7–)9–16(–20) mm, minutely hirtellous, hairs sometimes reduced to basal cells, or glabrous, throat strongly to weakly closing.

nodding 45–90º, not red-dotted, broadly elliptic-ovoid, inflated, sagittally compressed, (8–)14–18(–20) mm, glabrous or sparsely stipitate-glandular to hirsutulous, sometimes mixed glandular-hirsutulous, throat closing, adaxial lobe not distinctly longer than abaxial, not falcate.
Capsules

included, 6–9(–11) mm.

included, stipitate, 5–7 mm.
Anthers

included, glabrous.

included, glabrous.
2n

= 28, 56.

= 60.

Erythranthe microphylla

Erythranthe cordata
Phenology Flowering Mar–Jul. Flowering (Jan–)Mar–Jun(–Nov).
Habitat Rock depressions, rocky ridges, cliff faces, roadcuts, wet meadows, seeps, stream banks, drying ponds, ephemeral stream channels, vernal springs over serpentine, roadsides and roadside ditches, dry banks, lava soils, loam, clay, gravel, yellow pine, oak-pine, mixed oak woodlands, oak-chaparral. Springs, seeps, stream edges, muddy banks, flood plains, marshes and swamps, wash bottoms, wet depressions, wet places among boulders.
Elevation 20–1700(–2600) m. (100–5600(–8500) ft.) (600–)800–2400(–3000) m. ((2000–)2600–7900(–9800) ft.)
Distribution
from FNA
CA; ID; NV; OR; WA; BC
[WildflowerSearch map]
from FNA
AZ; CA; CO; NM; NV; TX; UT
[WildflowerSearch map]
Discussion

Erythranthe microphylla is characterized by its annual duration (fibrous-rooted), usually simple stems, relatively widely spaced leaves, glabrous or hirtellous vestiture, open corollas, and calyces closing at the throat. Even in the smallest corollas, the stigma is positioned above the adaxial anther pair, indicating that all are primarily allogamous. Some plants have basal and proximal cauline leaves with exaggeratedly and irregularly toothed-incised margins (especially in Lake and Napa counties, California, as in the types of Mimulus glareosus and M. guttatus var. insignis, respectively), but a similar tendency can be seen over most of the geographic range. Plants of E. microphylla vary greatly in height, leaf size, and flower size (the larger flowers approaching the size of those in E. grandis and E. decora), yet all seem to be within the expression of a single species.

An inversion sequence of chromosome 8 (the DIV1 region) is perfectly correlated with the life history features of at least four species of sect. Simiolus (D. B. Lowry and J. H. Willis 2010). One sequence occurs in Erythranthe guttata and E. grandis, which are perennial and rhizomatous, occur in habitats with year-round moisture, and flower relatively late in the season, while the opposite sequence occurs in E. nasuta and E. microphylla, which are annual and slender-taprooted or fibrous-rooted, occur in quickly drying habitats, and flower in early season. The inversion, with its tightly linked, locally adaptive alleles, contributes to isolating mechanisms between species with contrasting sequences and preserves the constellation of features that makes each a recognizable entity.

Hybridization and apparent introgression occur among Erythranthe guttata, E. microphylla, and E. nasuta, yet each remains distinct in duration, perennating morphology, and habit. Erythranthe arvensis (annual) also is a member of this gene-sharing group. A whole-genome analysis by A. D. Twyford and J. Friedman (2015) showed that populations of E. guttata and E. microphylla cluster together within each of several geographically delimited regions; they interpreted their trees as showing phylogenetic relationships and concluded that E. guttata and E. microphylla are conspecific. Other evidence (G. L. Nesom 2014c, 2014d), particularly the DIV1 inversion sequence, indicates that E. guttata and E. grandis are most closely related to each other and were derived from an ancestor of annual duration. Thus, E. microphylla and E. nasuta are morphologically and phylogenetically distinct from E. guttata, despite extensive gene flow where they are sympatric with it.

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

Erythranthe cordata is characterized by its fibrous-rooted habit (annual in duration, without rhizomes but commonly rooting at the proximal nodes), short corollas and autogamous reproduction (anthers and stigma at the same level), closed calyces, sparsely villous-glandular vestiture (lacking hirtellous, eglandular hairs), and stems commonly fistulose in larger plants. The short corollas and other features of autogamous reproduction of E. cordata are diagnostic and prominent. Plants of E. cordata are highly variable in size, from tiny fibrous-rooted plants with nearly filiform stems to much larger individuals with fistulose stems rooting at proximal nodes.

Erythranthe cordata and E. nasuta are sympatric in Arizona, southeastern New Mexico, and southern Utah, and small plants of each species may be similar in aspect, both with cleistogamous flowers and reduced vestiture. Erythranthe nasuta can be recognized by its distal and bracteal leaves with hirtellous to hirsutulous adaxial surfaces; a 10/x lens usually is required to see this feature, and it sometimes is most obvious around the leaf margins.

The common name of Erythranthe cordata alludes to a fancied resemblance of the corollas to the horn of a diminutive trumpet.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 17, p. 415. FNA vol. 17, p. 422.
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. 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. 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
Synonyms Mimulus microphyllus, M. glareosus, M. guttatus var. depauperatus, M. guttatus var. insignis, M. guttatus var. microphyllus, M. guttatus var. platycalyx, M. langsdorffii var. insignis, M. langsdorffii var. microphyllus, M. luteus var. depauperatus, M. nasutus var. insignis, M. platycalyx Mimulus cordatus, M. maguirei
Name authority (Bentham) G. L. Nesom: Phytoneuron 2012-39: 44. (2012) (Greene) G. L. Nesom: Phytoneuron 2012-39: 43. (2012)
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).



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