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round-leaf wild buckwheat, roundleaf buckwheat

California buckwheat, California wild buckwheat, eastern Mojave buckwheat, eastern Mojave wild buckwheat

Habit Herbs, spreading, annual, 0.5–4 dm, glabrous and often glaucous, greenish to grayish. Shrubs or subshrubs, compact to spreading or rounded and more or less erect, occasionally decumbent, infrequently scapose, (1–)2–15 × 2–25(–30) dm, tomentose to canescent, floccose, or glabrous.
Stems

caudex absent;

aerial flowering stems erect, solid, not fistulose, 0.1–0.5(–0.7) dm, glabrous.

sprawling or spreading to erect, often with persistent leaf bases, up to 1/2 or more height of plant;

caudex stems absent or matted to spreading;

aerial flowering stems erect to spreading, slender, solid, not fistulose, 0.3–2.5(–3) dm, tomentose, canescent, or glabrous.

Leaves

basal;

petiole 1.5–4 cm, floccose;

blade cordate to orbiculate, 1–2(–3) × 1–2.5(–3) cm, densely white-tomentose abaxially, floccose or subglabrous and greenish adaxially, margins plane.

cauline, 1 per node or fasciculate;

petiole 0.1–0.3 cm, canescent;

blade linear to linear-oblanceolate or oblanceolate, 0.6–1.5(–1.8) × 0.05–0.4(–0.6) cm, white-tomentose or canescent to subglabrous abaxially, tomentose or canescent and grayish, subglabrous, or glabrous and green adaxially, margins often revolute.

Inflorescences

cymose, open to diffuse, usually flat-topped, 5–35 × 5–35 cm;

branches glabrous;

bracts 3, scalelike, 1–2.5 × 0.5–2 mm.

cymose, infrequently cymose-umbellate or capitate, compact to open, occasionally flat-topped, 0.2–20 × 0.2–15 cm;

branches dichotomous, infrequently absent, tomentose to canescent or glabrous;

bracts usually 3, scalelike, triangular, and 1–3 mm, or leaflike, linear to oblanceolate, and 3–10 × 1–3 mm.

Peduncles

erect, straight, stoutish, 0.3–1.5 cm, glabrous.

absent.

Involucres

turbinate to campanulate, 1–2 × 1.5–2.5 mm, glabrous;

teeth 5, erect, 0.4–0.8 mm.

(1–)3–8 per cluster, turbinate to campanulate, 2–4 × 1.5–3 mm, canescent, pubescent, glabrous, or subglabrous;

teeth 5, erect, 0.3–1.2 mm.

Flowers

1–2.5 mm;

perianth white to pink with greenish to reddish midribs, becoming rose to red, glabrous;

tepals dimorphic, those of outer whorl flabellate, those of inner whorl lanceolate;

stamens included, 1.2–1.7 mm;

filaments pilose proximally.

2.5–3 mm;

perianth white to pinkish, glabrous or pubescent;

tepals connate proximal 1/4, monomorphic, usually elliptic to obovate;

stamens exserted, 2.5–5 mm;

filaments subglabrous or pubescent proximally.

Achenes

dark brown, 3-gonous, 1.5–2 mm, glabrous.

light brown to brown, 1.8–2.5 mm, glabrous.

2n

= 40.

Eriogonum rotundifolium

Eriogonum fasciculatum

Phenology Flowering May–Oct.
Habitat Sandy to gravelly flats and slopes, mixed grassland, saltbush, creosote bush, and mesquite communities, juniper woodlands
Elevation 600-1800 m (2000-5900 ft)
Distribution
from FNA
AZ; NM; TX; Mexico (Chihuahua, Coahuila)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NV; UT; including nw Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Eriogonum rotundifolium is the southern counterpart to E. cernuum, being common to abundant and occasionally even weedy. Its overall range, however, is significantly smaller. It occurs in Arizona only in Cochise County, but is found more widely in New Mexico, and is common in the trans-Pecos region of western Texas, with scattered populations in Dimmit, Ector, Foard, and Knox counties outside that region.

A sterile Edwin James specimen gathered in 1820 (NY) supposedly was collected near the Rocky Mountains and may be Eriogonum rotundifolium. Also seen at NY is an unattributed, redistributed collection of this species labeled only “Colorado.” Until better documented material from that state is seen, the species is considered not to be a member of the Colorado flora.

F. A. Elmore (1943) reported that the round-leaf wild buckwheat was used by the Navajo (Diné) people as an emetic. My own consumption of a few seeds, as a self-experiment, produced no particular urge to vomit. Inasmuch as the treatment was taken after swallowing ants, it is difficult to know whether the ants or the seeds were the emetic. G. M. Hocking (1956) reported that the leaves were used for sore throats and the stems were eaten raw (the latter proving in the same self-experiment not to be particularly tasty, leaving a slightly sour aftertaste). Hocking also reported that the roots were used medicinally but mentioned no specific ailment.

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

Varieties 5 (4 in the flora).

Eriogonum fasciculatum is a complex, polyploid series of variants that are generally distinct but often difficult to distinguish morphologically. Variety emphereium Reveal is confined to central Baja California, Mexico. The introduction of Eriogonum fasciculatum as a decorative roadside plant by the California Department of Transportation is resulting in hybrid populations involving E. cinereum. The aggressively weedy and (for Arizona) exotic variety foliosum is rapidly invading the native habitat of var. polifolium. Members of E. fasciculatum are food plants for several butterflies, notably the Bernardino dotted-blue (Euphilotes bernardino), lupine blue (Plebeius lupini), Mormon metalmark (Apodemia mormo), and Behr’s metalmark (A. virgulti). Probably the butterfly most commonly seen with the species is the nut-brown hairstreak (Satyrium saepium), which frequents plants in full flower. Eriogonum fasciculatum is also the most important native source of honey in California.

This widespread species was used extensively by Native Americans for a variety of ailments. Its application for pain and headaches (D. P. Barrows 1900; K. Hedges 1986; E. W. Voegelin 1938) was rather common, as was its general use for diarrhea (Hedges; Voegelin). M. L. Zigmond (1981) reported that the Kawaiisu lined their acorn granaries with leaves of var. proliferum to keep out rain—a daunting challenge given the size of the leaves! L. Hinton (1975) reported the use of a decoction of dried flowers and roots to maintain a healthy heart, and M. C. Stevenson (1915) indicated that a powder derived from the roots was used by the Zuñi to treat wounds, whereas a root decoction was taken for colds and hoarseness. B. R. Bocek (1984) reported that the Costanoan Indians of California used a decoction of the plant to treat unspecified urinary problems. F. H. Elmore (1943) reported the use of a decoction of var. proliferum by the Navajo (Diné) people as an anti-witchcraft medicine.

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

Key
1. Leaves thinly white-tomentose abaxially, glabrous adaxially; perianths and involucres mostly glabrous; plants usually decumbent; primarily coastal 80c. Eriogonum fasciculatum var. fasciculatum
→ 1
1. Leaves, perianths, and involucres pubescent or, if subglabrous, then plants of desert regions; plants erect to rounded; generally inland
→ 2
2. Leaves light yellow-green, subglabrous adaxially; involucres and perianths glabrous or subglabrous
var. flavoviride
2. Leaves dark green or grayish, usually pubescent adaxially; involucres and perianths pubescent
→ 3
3. Inflorescences capitate to cymose-umbellate, rarely cymose; leaves canescent on both surfaces or densely tomentose abaxially and canescent adaxially; leaf margins plane or infrequently revolute; mainly deserts
var. polifolium
3. Inflorescences open and mostly cymose; leaves densely white-tomentose abaxially, less so to green and floccose adaxially; leaf margins usually tightly revolute; mainly inner coastal foothills
var. foliolosum
Source FNA vol. 5, p. 402. FNA vol. 5, p. 297.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma 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. 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. 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. 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. fasciculatum var. flavoviride, E. fasciculatum var. foliolosum, E. fasciculatum var. polifolium
Synonyms E. cernuum subsp. glaucescens, E. cernuum subsp. rotundifolium, E. rotundifolium var. angustius
Name authority Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 21. (1856) Bentham: Trans. Linn. Soc. London 17: 411. (1836)
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