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Bentham's monkeyflower, small-leaf monkey-flower

Texas monkeyflower

Habit Annuals, fibrous-rooted. Annuals, fibrous-rooted, rooting at proximal nodes, sometimes forming matlike colonies.
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.

decumbent to decumbent-ascending basally, becoming fully erect at least in inflorescence, simple, sometimes few-branched from proximal nodes, usually distinctly fistulose, 10–30 cm, glabrous.

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 sometimes deciduous by flowering;

petiole: basal and proximals to mid cauline 10–70 mm, distals 0 mm;

blade palmately veined, ovate to broadly ovate or elliptic-ovate, becoming subreniform distally, (5–)15–35(–60) mm, distal closely paired, auriculate-subclasping, base truncate to subcordate, margins dentate-serrate to shallowly dentate, teeth 5–11 per side, apex obtuse to rounded, surfaces glabrous.

Flowers

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

plesiogamous, (6–)8–18(–24), often produced from all nodes, loosely to densely racemose, chasmogamous.

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, bilaterally symmetric, bilabiate;

tube-throat cylindric, 7–11 mm, exserted (1–)2–3(–4) mm beyond calyx margin;

limb slightly expanded.

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.

9–20 mm, glabrous, rarely sparsely 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.

purple-spotted, sometimes greenish, broadly cylindric-campanulate, inflated, sagittally compressed, 7–11 mm, glabrous, rarely minutely scabrous-hirtellous or sparsely stipitate-glandular, throat not closing, abaxial lobe slightly upcurving 10–45º, spreading 45º, or sometimes deflexed 40º.

Capsules

included, 6–9(–11) mm.

included, 4.5–6 mm.

Anthers

included, glabrous.

included, glabrous.

2n

= 28, 56.

= 60.

Erythranthe microphylla

Erythranthe inamoena

Phenology Flowering Mar–Jul. Flowering Jan–Apr(–Sep).
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. Edge of seeps and creeks, mud or gravel, shallow running water, wet crevices, canyon drainages.
Elevation 20–1700(–2600) m. (100–5600(–8500) ft.) 100–2400 m. (300–7900 ft.)
Distribution
from FNA
CA; ID; NV; OR; WA; BC
[WildflowerSearch map]
from FNA
TX; Mexico (Chihuahua, Coahuila)
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 inamoena is distinctive in its completely glabrous herbage, small corollas, flowers in racemes mostly at distal nodes and with reduced bracts, short and open-throated fruiting calyces, erect and fistulose stems, and apparent annual duration (fibrous-rooted but usually rooting at proximal cauline nodes).

Presumably because of its autogamous reproduction, Erythranthe inamoena has been confused with E. cordata, especially in the trans-Pecos region of Texas, where the two are sympatric. In contrast to E. cordata, E. inamoena usually has glabrous pedicels and calyces, flowers often produced from all nodes, smaller calyces [(7–)8–11 mm] that do not close at maturity, and corollas with a shorter tube-throat (7–11 mm).

Some populations in Brewster, Presidio, and Val Verde counties are identified here as Erythranthe inamoena (based on proximal-to-distal distribution of flowers and the short mature calyces with open throat) but have sparsely stipitate-glandular pedicels and calyces.

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

Source FNA vol. 17, p. 415. FNA vol. 17, p. 407.
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. 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. 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 inamoenus, M. jamesii var. texensis
Name authority (Bentham) G. L. Nesom: Phytoneuron 2012-39: 44. (2012) (Greene) G. L. Nesom: Phytoneuron 2012-39: 44. (2012)
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