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angle stem buckwheat, angle-stem wild buckwheat

clumping buckwheat, cushion desert wild buckwheat, mat wild buckwheat, Matted buckwheat, Matted wild buckwheat

Habit Herbs, erect to spreading, annual, 1–5(–10) dm, tomen-tose to floccose or glabrous, usually grayish. Herbs, matted, polygamodioecious, (0.1–)0.3–1 × 1–5(–12) dm.
Stems

caudex absent;

aerial flowering stems erect, striated, angled, solid, not fistulose, 0.5–1 dm, tomentose to floccose.

caudex spreading;

aerial flowering stems scapelike, ascending to weakly erect, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, (0.1–)0.3–0.8(–1) dm, mostly floccose or glabrous, without a whorl of bracts.

Leaves

basal and cauline;

basal: petiole 0.5–3 cm, mostly floccose, blade oblanceolate to oblong-lanceolate, 1–4(–4.5) × (0.2–)0.5–1(–1.3) cm, tomentose abaxially, floccose or glabrate and grayish or greenish adaxially, margins crenulate;

cauline sessile, blade lanceolate to oblong, 0.5–2 × 0.3–0.8 cm, similar to basal blade.

in compact basal rosettes;

petiole 0.05–0.4(–0.7) cm, usually tomentose;

blade elliptic to obovate or nearly oval, 0.2–1(–1.5) × 0.15–0.4(–0.5) cm, grayish- to whitish-tomentose on both surfaces or less so and greenish adaxially, margins entire, plane.

Inflorescences

cymose, open, 5–80 × 10–60 cm;

branches striated, angled, sparsely tomentose to glabrate;

bracts 3, scalelike, 1–3 × 1–3 mm.

capitate, 0.5–2 cm wide;

branches absent;

bracts absent immediately below involucre.

Peduncles

erect, straight, slender, 1–2 cm, sparsely tomentose to glabrous.

Involucres

turbinate-campanulate to campanulate, 1.5–2.5(–3) × 1.5–2.5(–3), sparsely puberulent;

teeth 5, erect, 0.3–0.6 mm.

1 per node, campanulate, 2–3.5 × 2–4 mm;

teeth 6–9, lobelike, strongly reflexed, 2–3.5 mm.

Flowers

1.5–1.8 mm;

perianth white to rose, without a conspicuous rose-purple spot on each outer tepal, minutely glandular-puberulent;

tepals dimorphic, those of outer whorl elliptic to obovate, sometimes inflated proximally, those of inner whorl narrowly spatulate;

stamens exserted, 2–3 mm;

filaments pilose proximally.

2.5–10 mm, including 0.5–1 mm stipelike base;

perianth yellow to reddish or rose, densely pilose to villous abaxially;

stamens exserted, 3–4 mm;

filaments pilose proximally; staminate flowers shorter, 2.5–4 mm, tepals monomorphic, oblong-oblanceolate; pistillate flowers 2.5–10 mm, tepals slightly dimorphic.

Achenes

light brown to brown, 3-gonous, 1–1.5 mm, glabrous.

light brown to brown, (3.5–)4–5 mm, glabrous or sparsely pubescent on beak.

Eriogonum angulosum

Eriogonum caespitosum

Phenology Flowering year-round. Flowering Apr–Jul.
Habitat Clayey flats and slopes, mixed grassland, saltbush, and chaparral communities, oak and conifer woodlands Sandy to gravelly flats and slopes, mixed grassland, saltbush, sagebrush, and mountain mahogany communities, oak, pinyon and/or juniper and montane conifer woodlands
Elevation 0-800 m (0-2600 ft) (1300-)1500-3000(-3700) m ((4300-)4900-9800(-12100) ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; ID; MT; NV; OR; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

The name Eriogonum angulosum has been applied to all of the members of its species complex except E. gossypinum. Since the 1950s, the name consistently has been applied to plants with long, exserted stamens and strongly angled stems of the Inner Coast Ranges (Alameda and Contra Costa counties south), the western foothills of the southern Sierra Nevada (Tulare County south), and the Central Valley (San Joaquin County south). The southern edge of the range is the northern foothills of the Transverse Ranges (Ventura and Los Angeles counties). The species can be common and occasionally abundant but rarely is weedy. A mixed collection (with E. gracillimum) from Barstow, San Bernardino County (K. Brandegee s.n., May 1913, UC), and two sheets of the species from San Diego gathered by Susan Stokes apparently in 1895 (B, SD) are discounted as to location.

In late fruit, the bractlets at the base of the pedicel inside the involucres of Eriogonum angulosum often elongate and broaden into oblanceolate segments that fill the involucre. As a result, the involucre appears to have several rows of teeth. This feature may be seen also in E. viridescens, but typically the involucres there appear to have only two or three rows of teeth. This feature is seen rarely in E. maculatum.

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

Eriogonum caespitosum is widespread and usually common. It is variable throughout its range but no taxonomic subunits have been noted. The functionally staminate plants can be morphologically different from the functionally pistillate ones, and that may cause some confusion in the field, especially when the latter are in fruit. The plants are widely cultivated and worthy of consideration for the rock or sand garden. Plants from along the eastern edge of the Sierra Nevada in southern Mono County, California, form large, dense mats and would be most attractive in the garden. The scapelike flowering stem is technically a peduncle, being a further reduction of the inflorescence from that seen in E. douglasii. A specimen supposedly gathered in Nebraska (Abbott s.n., CAS) is discounted as to location.

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

Source FNA vol. 5, p. 411. FNA vol. 5, p. 364.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum
Sibling taxa
E. abertianum, E. acaule, E. alatum, E. aliquantum, E. allenii, E. alpinum, E. ammophilum, E. ampullaceum, E. androsaceum, E. anemophilum, 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. 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. 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. sphaerocephalum var. sericoleucum
Name authority Bentham: Trans. Linn. Soc. London 17: 406, plate 18, fig. 1. (1836) Nuttall: J. Acad. Nat. Sci. Philadelphia 7: 50, plate 8, fig. 2. (1834)
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