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frosted buckwheat, frosted wild buckwheat

island buckwheat, Santa Cruz Island buckwheat, Santa Cruz Island wild buckwheat

Habit Herbs, matted, dioecious, 0.5–3 × 1–4 dm wide, tomentose to floccose. Shrubs, erect to spreading, 6–15(–20) × 5–30 dm, glabrous and cinereous, reddish.
Stems

caudex spreading;

aerial flowering stems erect or nearly so, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, 0.1–2(–2.5) dm, tomentose to floccose.

spreading to erect, occasionally with persistent leaf bases, up to 3/4 or more height of plant;

caudex stems absent;

aerial flowering stems erect, stout, solid, not fistulose, 0.5–1(–1.5) dm, glabrous.

Leaves

in loose to congested basal rosettes;

petiole (0.3–)0.5–1 cm, tomentose;

blade oblong to oblong-ovate or spatulate, 0.5–1.5 × 0.3–0.7 cm, densely white- or grayish-tomentose on both surfaces, sometimes greenish adaxially, margins entire, plane.

cauline, 1 per node;

petiole 0.1–0.5 cm, tomentose;

blade linear to narrowly oblong, 2–4(–5) × 0.1–0.4(–0.6) cm, white-tomentose abaxially, cinereous to glabrate and greenish adaxially, margins often revolute.

Inflorescences

capitate and 0.5–2 cm wide, mature pistillate plants open and umbellate, 1–3 × 1–4 cm;

branches tomentose to floccose;

bracts 2–6, leaflike, 0.1–0.5 × 0.1–0.3 cm, often absent immediately below involucre.

cymose, 5–10 × 5–15(–20) cm;

branches dichotomous, glabrous;

bracts 1–3, leaflike, lanceolate to oblong, 0.5–2 × 0.3–1.5 cm.

Peduncles

absent or erect, stout, 0.1–0.5 cm, cinereous.

Involucres

1 per node but occasionally appearing congested, turbinate-campanulate, 2.5–3 × 2–2.5 mm, tomentose;

teeth 5–8, erect, 0.5–1 mm.

1 per node, campanulate, 2–3 × 2.5–4 mm, cinereous;

teeth 5–7, erect, 0.5–1.5 mm.

Flowers

stipelike base 0.5–1 mm;

perianth yellow, glabrous; staminate flowers 2–3 mm, tepals ovate; pistillate flowers 4–6 mm, tepals oblanceolate, often becoming reddish in fruit;

stamens exserted, 2–3 mm;

filaments pilose proximally.

2–3.5(–4) mm;

perianth white to pinkish, villous abaxially;

tepals connate proximally, monomorphic, oblanceolate to narrowly obovate;

stamens exserted, 3–5 mm;

filaments glabrous.

Achenes

light brown to brown, 3–3.5 mm, glabrous except for sparsely pubescent beak.

brown, 2.5–3.5 mm, glabrous.

2n

= 40.

Eriogonum incanum

Eriogonum arborescens

Phenology Flowering Jun–Sep. Flowering Apr–Oct.
Habitat Sandy to gravelly or rocky granitic or occasionally volcanic flats, slopes, and outcrops, mixed grassland, manzanita, and sagebrush communities, montane conifer woodlands Rocky slopes and canyon walls, coastal scrub communities
Elevation (1900-) 2100-4000 m ((6200-) 6900-13100 ft) 10-600 m (0-2000 ft)
Distribution
from FNA
CA; NV
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
Discussion

Eriogonum incanum is common throughout the central and southern Sierra Nevada of California (Alpine, El Dorado, Fresno, Inyo, Madera, Mariposa, Nevada, Tulare, and Tuolumne counties) and extreme west-central Nevada (Carson City, Douglas, and Washoe counties). It is a food plant for the green hairstreak butterfly (Callophrys lemberti), the Pacific dotted-blue (Euphilotes enoptes), and the gorgon copper (Gaeides gorgon).

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

Of conservation concern.

Eriogonum arborescens is local and occasionally rare on Santa Cruz, Santa Rosa, and Anacapa islands in Santa Cruz and Ventura counties. The species is cultivated, and populations have become naturalized on the mainland from San Mateo County south to San Diego, in large part because of planting along highways. Every effort should be made to remove these naturalized populations from the mainland.

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

Source FNA vol. 5, p. 366. FNA vol. 5, p. 302.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum 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. 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
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. 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. 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
Synonyms E. marifolium var. incanum, E. ursinum var. rosulatum
Name authority Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 161. (1870) Greene: Bull. Calif. Acad. Sci. 1: 11. (1884)
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