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slender buckwheat, slender wild buckwheat

bare-stem buckwheat, barestem wild buckwheat, naked buckwheat, naked wild buckwheat, nude buckwheat

Habit Subshrubs or shrubs, erect to spreading, not scapose, 0.2–1.5 × (0.6–)1–13(–16) dm, white- to tannish-tomentose, floccose, or glabrous. Herbs, mostly erect, infrequently scapose, (0.5–)1–15(–20) × 0.5–3 dm, glabrous or floccose to tomentose, usually greenish, occasionally grayish.
Stems

spreading to erect, typically without persistent leaf bases, up to 1/2 height of plant;

caudex stems absent or spreading;

aerial flowering stems erect to spreading, slender, solid, not fistulose, 0.05–1.5 dm, lanate, tomentose, floccose, subglabrous, or glabrous.

spreading to erect, with or without persistent leaf bases, up to 1/4 height of plant;

caudex stems absent;

aerial flowering stems erect to spreading, slender to stout, solid or hollow, occasionally fistulose, 0.3–4(–10) dm, glabrous or lanate to tomentose or floccose.

Leaves

cauline, 1 per node or fasciculate;

petiole 0.1–0.5 cm, tomentose to floccose or glabrous;

blade usually elliptic, sometimes linear to obovate, 0.3–3.5 × (0.07–)0.1–1.2 cm, tomentose abaxially, less so or glabrous adaxially, margins occasionally revolute.

basal or sheathing up stem 0.5–4 dm;

petiole 1–10 cm, glabrous or tomentose;

blade oblanceolate to elliptic or ovate, 1–6 × (0.3–)1–4 cm, densely white-lanate or tomentose abaxially, tomentose to floccose or subglabrous to glabrous adaxially, margins plane or undulate-crisped.

Inflorescences

cymose, compact, often flat-topped, 0.5–6(–12) × 1–10(–13) cm;

branches dichotomous, whitish-lanate to brownish- or reddish-tomentose to floccose or glabrate, infrequently green or gray and subglabrous or glabrous;

bracts 3, scalelike, linear to triangular, 1–5 mm.

cymose, rarely umbellate or capitate, 2–100(–150) × 2–40(–80) cm;

branches usually dichotomous, glabrous or tomentose to floccose or sparsely pubescent;

bracts 3, scalelike, 0.5–3(–5) mm.

Peduncles

absent or mostly erect, slender, 0.3–1.5 cm, tomentose to floccose.

absent.

Involucres

1 per node, turbinate, (1.5–)2–3.5(–4) × 1.3–2.5(–3) mm, tomentose, floccose, subglabrous, or glabrous;

teeth 5, erect, (0.3–)0.5–1(–1.7) mm.

1 per node or 2–10 per cluster, turbinate to turbinate-campanulate, (2.5–)3–5(–7) × (1.5–)2–4 mm, glabrous, tomentose, or sparsely pubescent;

teeth 5–8, 0.2–0.6 mm.

Flowers

1.5–3(–4) mm;

perianth yellow or white to pink, orange, rose, red, or occasionally cream, glabrous;

tepals connate proximal 1/5–2/5, essentially monomorphic, oblong to obovate;

stamens usually exserted, 2.5–4 mm;

filaments sparsely to densely puberulent proximally.

(1.5–)2–4 mm;

perianth white or yellow, sometimes pink or rose, glabrous or pubescent;

tepals connate proximal 1/4, monomorphic, oblong to obovate;

stamens exserted, 2–5 mm;

filaments pilose proximally.

Achenes

brown, 1.5–3 mm, glabrous.

light brown to brown, 1.5–3.5 mm, glabrous.

Eriogonum microthecum

Eriogonum nudum

Distribution
from FNA
AZ; CA; CO; ID; MT; NM; NV; OR; UT; WA; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; NV; OR; WA; nw Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 13 (13 in the flora).

Eriogonum microthecum is used as browse by deer and to a lesser degree by cattle and sheep. Some forms are now in cultivation. The species is reportedly used by the Piute of Nevada in the treatment of tuberculosis, lameness, rheumatism, and bladder trouble (P. Train et al. 1941). S. A. Weber and P. D. Seaman (1985) stated that A. F. Whiting found the plants being used as a tea by the Havasupai in northern Arizona. Members of E. microthecum are food plants for subspecies of the rare pallid blue butterfly (Euphilotes pallescens). Also found on this species is the cythera metalmark (Apodemia mormo cythera). Some authors have referred E. effusum to this species, even though the ranges of the two species do not overlap and intermediates are unknown.

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

Varieties 13 (13 in the flora).

Several local groups of Native Americans in California used members of this species in a variety of ways. S. A. Barrett and E. W. Gifford (1933) and S. M. Schenck and E. W. Gifford (1952) reported the consumption of raw young stems that are rather moist and tasty, although there is a sour aftertaste. The Kawaiisu used the hollow stems (probably var. westonii, rather than var. pauciflorum) as drinking tubes and as pipes (M. L. Zigmond 1981). Zigmond reported also that the roots of var. pauciflorum are used as an infusion for coughs.

Members of Eriogonum nudum are food plants for the Bauer’s dotted-blue butterfly (Euphilotes baueri), the Pacific dotted-blue (E. enoptes), the gorgon copper (Gaeides gorgon), and the Mormon metalmark (Apodemia mormo).

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

Key
1. Perianths yellow
→ 2
1. Perianths various shades of white, cream, orange, pink, or red, not yellow
→ 4
2. Flowering stems and inflorescence branches usually glabrous; e Oregon and wc Idaho
var. microthecum
2. Flowering stems and inflorescence branches tomentose to floccose; se Oregon and sw Idaho s to e California and w Nevada
→ 3
3. Leaf blades (0.2-)0.3-0.6(-0.8) cm wide; flowers (1.5-)2-2.5(-3) mm; involucres 2-2.5 mm; achenes 1.5-2 mm; se Oregon and sw Idaho s to e California and w Nevada
var. ambiguum
3. Leaf blades 0.5-1.2 cm wide; flowers 2.5-3 mm; involucres 2.5-4 mm; achenes 2.5-3 mm; ne California, nw Nevada
var. schoolcraftii
4. Tomentum whitish (see also var. alpinum of the Sierra Nevada, California); flowering stems and inflorescence branches infrequently glabrous
→ 5
4. Tomentum brownish or reddish (may be white in var. alpinum), or flowering stems and inflorescence branches essentially glabrous
→ 6
5. Leaf margins not revolute; flowering inflorescence branches floccose or glabrous; northern phase of species
var. laxiflorum
5. Leaf margins revolute or nearly so; flowering inflorescence branches lanate to tomentose, or if subglabrous or glabrous, then southern phase of species
var. simpsonii
6. Plants shrubs, 3-6 dm
→ 7
6. Plants subshrubs, 0.2-1.5(-2) dm
→ 8
7. Flowering stems and inflorescence branches tomentose when young, becoming floccose at maturity; flowers 1.5-2(-2.5) mm; achenes 1.8-2 mm; Death Valley region, California
var. panamintense
7. Flowering stems and inflorescence branches lanate to tomentose at maturity; flowers 2-2.5(-3) mm; achenes 2.5-3 mm; Transverse Ranges, California
E. microthecumvar. corymbosoides
8. Leaf blades elliptic or ovate, margins not revolute; flowers (1.5-)2-3.5(-4) mm
→ 9
8. Leaf blades linear or linear-oblanceolate to narrowly elliptic, margins often revolute; flowers 1.5-2.5 mm
→ 10
9. Leaf blades 0.5-1 × (0.2-)0.3-0.5(-0.6) cm; involucres (2-)2.5-3 mm; flowers (2.5-)3-3.5(-4) mm; San Gabriel Mountains, California
var. johnstonii
9. Leaf blades 0.3-0.7(-0.8) × 0.1-0.4 cm; involucres 2.5-3.5 mm; flowers (1.5-)2-3.5 mm; desert ranges of se California, c Nevada, and Utah1f. Eriogonum microthecum var. lapidicola [8. Shifted to left margin—Ed.]
→ 8
10. Involucres 3-4 mm; perianths cream; San Bernardino Mountains, California
var. lacus-ursi
10. Involucres (1.5-)2-3 mm; perianths white, pink, red, or rose; Sierra Nevada of California, or e Nevada and w Utah
→ 11
11. Flowering stems glabrous; leaf blades sparsely floccose or glabrous adaxially; desert ranges, se Nevada
var. arceuthinum
11. Flowering stems white- to brownish-floccose to subglabrous, or reddish-tomentose to floccose; leaf blades floccose to subglabrous adaxially; California or wc Utah
→ 12
12. Tomentum white to brownish; Sierra Nevada, California
var. alpinum
12. Tomentum reddish; desert ranges, wc Utah
var. phoeniceum
1. Involucres and inflorescence branches tomentose to floccose; leaves usually basal
→ 2
1. Involucres and inflorescence branches glabrous or, if pubescent, leaves sheathing up stems
→ 3
2. Perianths white; flowering stems lanate to tomentose; leaf blades 2-3.5 cm; s Sierra Nevada
var. regirivum
2. Perianths yellow or white to rose; flowering stems tomentose to floccose; leaf blades 2-4 cm; s Oregon, n California, wc Nevada
var. oblongifolium
3. Leaves sheathing up stems, margins often strongly undulate-crisped
→ 4
3. Leaves basal, margins plane or slightly undulate-crisped
→ 8
4. Flowering stems tomentose
→ 5
4. Flowering stems glabrous
→ 6
5. Perianths pubescent; flowers 1.5-2 mm; involucres 3-4 mm; Sierra Nevada, California
var. regirivum
5. Perianths glabrous; flowers 3-4 mm; involucres 4-6 mm; Coast Ranges, California
var. decurrens
6. Leaf blades densely lanate abaxially, tomentose adaxially; involucres 5-10 per cluster; Sierra Nevada, California
var. murinum
6. Leaf blades tomentose abaxially, less so to floccose, glabrous, or nearly so adaxially; involucres 1 per node or 2-5 per cluster; widespread, Coast Ranges, California
→ 7
7. Flowering stems occasionally fistulose; involucres (2-)3-5 per cluster; perianths white to pink, rarely yellowish
var. auriculatum
7. Flowering stems strongly fistulose; involucres 1 per node; perianths pale yellowish white to yellow or white
var. indictum
8. Involucres 1(-2) per cluster
var. westonii
8. Involucres 2-10 per cluster
→ 12
9. Flowering stems fistulose; perianths yellow, infrequently white; c California
var. westonii
9. Flowering stems not fistulose or, if so, plants of sw California; perianths white, rarely yellow
→ 10
10. Perianths pubescent or, infrequently, glabrous; s California
var. pauciflorum
10. Flowers glabrous; sw Oregon, n California, Nevada
→ 11
11. Leaf blades 1-5 cm; sw Oregon, n California (including w slope of Sierra Nevada), Washington
var. nudum
11. Leaf blades 1-2 cm; Sierra Nevada of California and adjacent desert ranges of wc Nevada
var. deductum
12. Perianths pubescent, often yellow
→ 13
12. Perianths usually glabrous abaxially, white, rarely yellow
→ 14
13. Flowering stems not fistulose; leaf blades floccose or glabrous adaxially, margins plane; plants of nonaridregions
var. pubiflorum
13. Flowering stems slightly to distinctly fistulose; leaf blades tomentose to floccose adaxially, margins undulate-crisped; plants of arid regions
var. westonii
14. Inflorescences capitate or nearly so; alpine, Sierra Nevada
E. nudumvar. scapigerum
14. Inflorescences cymose or, if capitate, not alpine.
→ 15
15. Involucres 1(-2) per cluster, 5- 7 mm; mountains of s California
var. pauciflorum
15. Involucres 2-10 per cluster, 3-5 mm; mountains and foothills of c and n California or coastal bluffs. [16. Shifted to left margin—Ed.]
→ 16
16. Inflorescences cymose and branched 2 or more times; involucres 2-5 per cluster; mountains and foothills of c and n California, Oregon, and Washington.
var. nudum
16. Inflorescences capitate or cymose and branched 1-2 times; involucres 5-10 per cluster; coastal bluffs, sw Oregon, ne California
var. paralinum
Source FNA vol. 5, p. 242. FNA vol. 5, p. 309.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla
Sibling taxa
E. abertianum, E. acaule, E. alatum, E. aliquantum, E. allenii, E. alpinum, E. ammophilum, E. ampullaceum, E. androsaceum, E. anemophilum, E. angulosum, E. annuum, E. apiculatum, E. apricum, E. arborescens, E. arcuatum, E. aretioides, E. argillosum, E. argophyllum, E. arizonicum, E. artificis, E. atrorubens, E. baileyi, E. batemanii, E. bicolor, E. bifurcatum, E. brachyanthum, E. brachypodum, E. brandegeei, E. breedlovei, E. brevicaule, E. butterworthianum, E. caespitosum, E. capillare, E. cernuum, E. chrysops, E. cinereum, E. cithariforme, E. clavatum, E. clavellatum, E. codium, E. collinum, E. coloradense, E. compositum, E. concinnum, E. congdonii, E. contiguum, E. contortum, E. correllii, E. corymbosum, E. covilleanum, E. crocatum, E. cronquistii, E. crosbyae, E. cusickii, E. darrovii, E. dasyanthemum, E. davidsonii, E. deflexum, E. deserticola, E. desertorum, E. diatomaceum, E. diclinum, E. divaricatum, E. douglasii, E. eastwoodianum, E. effusum, E. elatum, E. elegans, E. elongatum, E. ephedroides, E. eremicola, E. eremicum, E. ericifolium, E. esmeraldense, E. evanidum, E. exaltatum, E. exilifolium, E. fasciculatum, E. flavum, E. fusiforme, E. giganteum, E. gilmanii, E. glandulosum, E. gordonii, E. gossypinum, E. gracile, E. gracilipes, E. gracillimum, E. grande, E. greggii, E. gypsophilum, E. havardii, E. heermannii, E. helichrysoides, E. hemipterum, E. heracleoides, E. hieracifolium, E. hirtellum, E. hirtiflorum, E. hoffmannii, E. holmgrenii, E. hookeri, E. howellianum, E. hylophilum, E. incanum, E. inerme, E. inflatum, E. intrafractum, E. jamesii, E. jonesii, E. kelloggii, E. kennedyi, E. kingii, E. lachnogynum, E. lancifolium, E. latens, E. latifolium, E. lemmonii, E. leptocladon, E. leptophyllum, E. libertini, E. lobbii, E. loganum, E. lonchophyllum, E. longifolium, E. luteolum, E. maculatum, E. mancum, E. marifolium, E. mensicola, E. mitophyllum, E. mohavense, E. molestum, E. mortonianum, E. multiflorum, E. natum, E. nealleyi, E. nervulosum, E. nidularium, E. niveum, E. nortonii, E. novonudum, E. nudum, E. nummulare, E. nutans, E. ochrocephalum, E. ordii, E. ostlundii, E. ovalifolium, E. palmerianum, E. panamintense, E. panguicense, E. parishii, E. parvifolium, E. pauciflorum, E. pelinophilum, E. pendulum, E. pharnaceoides, E. plumatella, E. polycladon, E. polypodum, E. prattenianum, E. prociduum, E. pulchrum, E. pusillum, E. pyrolifolium, E. racemosum, E. reniforme, E. ripleyi, E. rixfordii, E. robustum, E. rosense, E. roseum, E. rotundifolium, E. rubricaule, E. rupinum, E. salicornioides, E. saxatile, E. scabrellum, E. scopulorum, E. shockleyi, E. siskiyouense, E. smithii, E. soliceps, E. soredium, E. spathulatum, E. spectabile, E. spergulinum, E. sphaerocephalum, E. strictum, E. subreniforme, E. suffruticosum, E. temblorense, E. tenellum, E. ternatum, E. terrenatum, E. thomasii, E. thompsoniae, E. thornei, E. thurberi, E. thymoides, E. tiehmii, E. tomentosum, E. trichopes, E. tripodum, E. truncatum, E. tumulosum, E. twisselmannii, E. umbellatum, E. ursinum, E. vestitum, E. villiflorum, E. vimineum, E. viridescens, E. viridulum, E. viscidulum, E. visheri, E. watsonii, E. wetherillii, E. wootonii, E. wrightii, E. zionis
E. abertianum, E. acaule, E. alatum, E. aliquantum, E. allenii, E. alpinum, E. ammophilum, E. ampullaceum, E. androsaceum, E. anemophilum, E. angulosum, E. annuum, E. apiculatum, E. apricum, E. arborescens, E. arcuatum, E. aretioides, E. argillosum, E. argophyllum, E. arizonicum, E. artificis, E. atrorubens, E. baileyi, E. batemanii, E. bicolor, E. bifurcatum, E. brachyanthum, E. brachypodum, E. brandegeei, E. breedlovei, E. brevicaule, E. butterworthianum, E. caespitosum, E. capillare, E. cernuum, E. chrysops, E. cinereum, E. cithariforme, E. clavatum, E. clavellatum, E. codium, E. collinum, E. coloradense, E. compositum, E. concinnum, E. congdonii, E. contiguum, E. contortum, E. correllii, E. corymbosum, E. covilleanum, E. crocatum, E. cronquistii, E. crosbyae, E. cusickii, E. darrovii, E. dasyanthemum, E. davidsonii, E. deflexum, E. deserticola, E. desertorum, E. diatomaceum, E. diclinum, E. divaricatum, E. douglasii, E. eastwoodianum, E. effusum, E. elatum, E. elegans, E. elongatum, E. ephedroides, E. eremicola, E. eremicum, E. ericifolium, E. esmeraldense, E. evanidum, E. exaltatum, E. exilifolium, E. fasciculatum, E. flavum, E. fusiforme, E. giganteum, E. gilmanii, E. glandulosum, E. gordonii, E. gossypinum, E. gracile, E. gracilipes, E. gracillimum, E. grande, E. greggii, E. gypsophilum, E. havardii, E. heermannii, E. helichrysoides, E. hemipterum, E. heracleoides, E. hieracifolium, E. hirtellum, E. hirtiflorum, E. hoffmannii, E. holmgrenii, E. hookeri, E. howellianum, E. hylophilum, E. incanum, E. inerme, E. inflatum, E. intrafractum, E. jamesii, E. jonesii, E. kelloggii, E. kennedyi, E. kingii, E. lachnogynum, E. lancifolium, E. latens, E. latifolium, E. lemmonii, E. leptocladon, E. leptophyllum, E. libertini, E. lobbii, E. loganum, E. lonchophyllum, E. longifolium, E. luteolum, E. maculatum, E. mancum, E. marifolium, E. mensicola, E. microthecum, E. mitophyllum, E. mohavense, E. molestum, E. mortonianum, E. multiflorum, E. natum, E. nealleyi, E. nervulosum, E. nidularium, E. niveum, E. nortonii, E. novonudum, E. nummulare, E. nutans, E. ochrocephalum, E. ordii, E. ostlundii, E. ovalifolium, E. palmerianum, E. panamintense, E. panguicense, E. parishii, E. parvifolium, E. pauciflorum, E. pelinophilum, E. pendulum, E. pharnaceoides, E. plumatella, E. polycladon, E. polypodum, E. prattenianum, E. prociduum, E. pulchrum, E. pusillum, E. pyrolifolium, E. racemosum, E. reniforme, E. ripleyi, E. rixfordii, E. robustum, E. rosense, E. roseum, E. rotundifolium, E. rubricaule, E. rupinum, E. salicornioides, E. saxatile, E. scabrellum, E. scopulorum, E. shockleyi, E. siskiyouense, E. smithii, E. soliceps, E. soredium, E. spathulatum, E. spectabile, E. spergulinum, E. sphaerocephalum, E. strictum, E. subreniforme, E. suffruticosum, E. temblorense, E. tenellum, E. ternatum, E. terrenatum, E. thomasii, E. thompsoniae, E. thornei, E. thurberi, E. thymoides, E. tiehmii, E. tomentosum, E. trichopes, E. tripodum, E. truncatum, E. tumulosum, E. twisselmannii, E. umbellatum, E. ursinum, E. vestitum, E. villiflorum, E. vimineum, E. viridescens, E. viridulum, E. viscidulum, E. visheri, E. watsonii, E. wetherillii, E. wootonii, E. wrightii, E. zionis
Subordinate taxa
E. microthecum var. alpinum, E. microthecum var. ambiguum, E. microthecum var. arceuthinum, E. microthecum var. johnstonii, E. microthecum var. lacus-ursi, E. microthecum var. laxiflorum, E. microthecum var. microthecum, E. microthecum var. panamintense, E. microthecum var. phoeniceum, E. microthecum var. schoolcraftii, E. microthecum var. simpsonii, E. microthecumvar. corymbosoides
E. nudum var. auriculatum, E. nudum var. decurrens, E. nudum var. deductum, E. nudum var. indictum, E. nudum var. murinum, E. nudum var. nudum, E. nudum var. oblongifolium, E. nudum var. paralinum, E. nudum var. pauciflorum, E. nudum var. pubiflorum, E. nudum var. regirivum, E. nudum var. westonii, E. nudumvar. scapigerum
Synonyms E. latifolium subsp. nudum
Name authority Nuttall: Proc. Acad. Nat. Sci. Philadelphia 4: 15. (1848) Douglas ex Bentham: Trans. Linn. Soc. London 17: 413. (1836)
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