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Blue Mountain buckwheat, strict buckwheat

clay buckwheat, clay loving buckwheat, Coast Range wild buckwheat

Habit Herbs, erect, loosely to densely matted, not scapose, 1–5 × 1–10 dm, tomentose or glabrous. Herbs, erect, 1–3 dm, glabrous or rarely sparsely floccose, mostly greenish.
Stems

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

caudex stems absent or spreading to matted;

aerial flowering stems erect to spreading, slender, solid, not fistulose, 1–3 dm, tomentose or glabrous.

aerial flowering stems erect, (0.3–)0.5–1.5(–2.5) dm, glabrous, rarely sparsely floccose.

Leaves

basal, 1 per node;

petiole rarely twisted or curled, 1–6 cm, mostly tomentose;

blade elliptic to ovate, 0.5–2.5(–4) × (0.3–)0.5–1.5 cm, lanate, tomentose to floccose on both surfaces, sometimes sparsely tomentose to floccose and greenish or floccose to subglabrous or glabrous adaxially, margins plane.

basal and cauline;

basal: petiole (0.5–)1–4(–5) cm, sparsely floccose, blade oblong, 1–3(–5) × 0.3–1.2(–1.6) cm, densely white-tomentose abaxially, floccose to glabrate and greenish adaxially;

cauline: petiole 0.3–2 cm, sparsely floccose, blade elliptic to oblong, 0.5–1.5 × 0.2–0.8 cm, similar to basal blade.

Inflorescences

umbellate-cymose to cymose, 1–20 × 3–25 cm;

branches dichotomous, tomentose to floccose or less often glabrous;

bracts 3, scalelike, triangular, 1–3 mm.

cymose, occasionally distally uniparous due to suppression of secondary branches, open, (2–)5–20(–25) cm;

branches glabrous or rarely sparsely floccose;

bracts 1–5(–7) × 0.5–1(–1.5) mm.

Peduncles

absent.

erect, straight, slender, 0.5–4.5(–6) cm, glabrous.

Involucres

1 per node, rarely 2–5 per cluster, narrowly turbinate to turbinate-campanulate, 4–6 × 1.5–5 mm, tomentose or glabrous;

teeth 5, erect, 0.5–1.3 mm.

terminal at tips of slender branchlets proximally, not appressed to branches, turbinate, (2–)2.5–3 × 2–3 mm, glabrous;

teeth 5, erect, 0.2–0.5 mm.

Flowers

3–5(–6) mm;

perianth yellow or white to rose or purple, glabrous;

tepals connate proximally, dimorphic, those of outer whorl elliptic to nearly orbiculate, 2–3 × 2–3 mm, those of inner whorl oblanceolate to oblong, 3–4 × 1–2 mm;

stamens included to slightly exserted, 2–5 mm;

filaments pilose proximally.

1.5–2 mm;

perianth white to rose, glabrous;

tepals monomorphic, oblong;

stamens mostly included, 1–2 mm;

filaments glabrous;

styles 0.2–0.3 mm.

Achenes

light brown to brown, 3–3.5 mm, glabrous.

brown, 3-gonous, 2–2.5 mm, glabrous;

beak smooth.

Eriogonum strictum

Eriogonum argillosum

Phenology Flowering Mar–Oct.
Habitat Clay to serpentine outcrops and slopes, mixed grassland and chaparral communities, oak and pine woodlands
Elevation 100-600 m (300-2000 ft)
Distribution
from FNA
CA; ID; MT; NV; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

Eriogonum strictum, E. niveum, and E. ovalifolium form a complex of closely related species differing in leaf, inflorescence branching, and flower features. Variety proliferum appears to be the basal entity of the complex, approaching both E. niveum and E. ovalifolium var. pansum in its pubescence and branching pattern. Also, specimens of var. proliferum are sometimes difficult to differentiate from E. nudum var. oblongifolium. Careful observation, though, will permit well-made collections to be easily distributed among the individual species. An alternative taxonomy is to reduce all of the taxa to E. ovalifolium and recognize a series of subspecies and varieties. It is possible that additional study will show that E. strictum is sufficiently distinct from its tomentose to floccose counterparts to justify recognition of E. proliferum. In that case, both var. anserinum and var. greenei would be assigned to the latter species. Or, one could follow C. L. Hitchcock et al. (1955–1969, vol. 2) and recognize subsp. strictum as distinct from subsp. proliferum, with the latter consisting of varieties proliferum, anserinum, and greenei.

Members of the Eriogonum strictum are food plants for the Bauer’s dotted-blue butterfly (Euphilotes baueri).

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

Eriogonum argillosum is rare to locally infrequent in coastal central California. It was last seen in Santa Clara County in 1895 and now is almost certainly extirpated there. Otherwise, it is found in the San Benito River Canyon (San Benito County) area and east of San Lucas (Monterey County). This is the most distinct of the five species in the E. eastwoodianum complex.

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

Key
1. Inflorescence branches glabrous
var. strictum
1. Inflorescence branches tomentose to floccose
→ 2
2. Perianths yellow
var. anserinum
2. Perianths white to rose or purple
→ 3
3. Leaf blades grayish-tomentose to floccose on both surfaces, or greenish-tomentose to floccose adaxially
var. proliferum
3. Leaf blades densely whitish-lanate to tomentose on both surfaces
var. greenei
Source FNA vol. 5, p. 317. FNA vol. 5, p. 419.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oregonium
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. 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. 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. 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. 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. 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
Subordinate taxa
E. strictum var. anserinum, E. strictum var. greenei, E. strictum var. proliferum, E. strictum var. strictum
Name authority Bentham: Trans. Linn. Soc. London 17: 414. (1836) J. T. Howell: Leafl. W. Bot. 1: 13. (1932)
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