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

Butterworth's buckwheat, Butterworth's wild buckwheat

Habit Shrubs, erect to spreading, 6–15(–20) × 5–30 dm, glabrous and cinereous, reddish. Subshrubs, rarely scapose, 1–3 × 1–4 dm, tomentose, grayish to reddish.
Stems

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.

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

caudex stems absent;

aerial flowering stems erect, slender, solid, not fistulose, 0.1–0.3 dm, tomentose.

Leaves

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.

sheathing up stem 0.5–1.5 cm, 1 per node;

petiole 0.1–0.3 cm, tomentose;

blade linear to narrowly elliptic, (0.5–)1–2 × 0.1–0.4 cm, grayish- to reddish-brown-tomentose, margins revolute.

Inflorescences

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.

cymose-umbellate to cymose, rarely capitate, often with involucres racemosely disposed at tips, usually 1–2 × 1–2 cm;

branches dichotomous, rarely scapelike, tomentose;

bracts 3, scalelike, narrowly triangular, (1–)2–4(–5) mm.

Peduncles

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

absent.

Involucres

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

teeth 5–7, erect, 0.5–1.5 mm.

1 per node, turbinate to turbinate-campanulate, (4–)5–6 × 3–4 mm, tomentose;

teeth 5, erect, 1–2 mm.

Flowers

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.

(3–)4–5 mm;

perianth ochroleucous to rose, glabrous;

tepals connate proximal 1/4, monomorphic, obovate;

stamens exserted, 5–6 mm;

filaments pubescent proximally.

Achenes

brown, 2.5–3.5 mm, glabrous.

brown, 3–3.5 mm, glabrous.

2n

= 40.

Eriogonum arborescens

Eriogonum butterworthianum

Phenology Flowering Apr–Oct. Flowering Jun–Sep.
Habitat Rocky slopes and canyon walls, coastal scrub communities Sandstone outcrops, chaparral communities, oak and conifer woodlands
Elevation 10-600 m (0-2000 ft) 600-700 m (2000-2300 ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

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.)

Of conservation concern.

Eriogonum butterworthianum is a rare and localized species that grows in the cracks of Vaqueros sandstone near The Indians in the Santa Lucia Range of Monterey County. It is considered a “sensitive species” by the U.S. Forest Service. Its relationship to other species in subg. Eucycla is uncertain. Butterworth’s wild buckwheat would make an elegant addition to the garden. Given its rarity, great care must be taken even in collecting seeds.

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

Source FNA vol. 5, p. 302. FNA vol. 5, p. 294.
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. 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
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. 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
Name authority Greene: Bull. Calif. Acad. Sci. 1: 11. (1884) J. T. Howell: Leafl. W. Bot. 9: 153. (1961)
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