Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Eriogonum racemosum

Polygonaceae

red-root wild buckwheat, redroot buckwheat

buckwheat family
Habit Herbs, erect to slightly spreading, 3–8(–10) × 0.5–1.5 dm, tomen-tose to floccose or rarely glabrous, grayish. Trees, shrubs, vines, or herbs, perennial, biennial, or annual, homophyllous (heterophyllous in some species of Polygonum), polycarpic (rarely monocarpic in Eriogonum); roots fibrous or a solid or, rarely, chambered taproot, rarely tuberous.
Stems

spreading to erect, without persistent leaf bases, up to 1/6 height of plant;

caudex stems absent;

aerial flowering stems erect to slightly spreading, slender to stout, solid, not fistulose, (1–)1.5–2.5(–3) dm, tomentose to floccose, rarely glabrous.

prostrate to erect, sometimes scandent or scapose, solid or hollow, rarely with recurved spines (some species of Persicaria), glabrous or pubescent, sometimes glandular;

nodes swollen or not;

tendrils absent (except in Antigonon and Brunnichia);

branches free (adnate to stems distal to nodes and appearing to arise internodally in Polygonella);

caudex stems (subfam.
Leaves

basal, 1 per node;

petiole (2–)3–10(–15) cm, tomentose to floccose;

blade elliptic to ovate or oval to nearly rotund, (1.5–)2–6(–10) × 1–4(–5) cm, lanate to thinly tomentose abaxially, floccose or glabrous and green adaxially, margins plane.

deciduous (persistent in Coccoloba and sometimes more than 1 year in Antigonon, Eriogonum, Chorizanthe, and Polygonella), basal or basal and cauline, rosulate, mostly alternate, infrequently opposite or whorled;

stipule (ocrea) absent (subfam.
Inflorescences

virgate or racemose with involucres racemosely disposed throughout or at tips, 15–50 × 05–20 cm, tomentose, rarely glabrous;

branches dichotomous, upper secondaries suppressed and bearing 5–20(–30) racemosely arranged involucres;

bracts 3, scalelike, triangular, and (1–)2.5–7 mm, or leaflike, linear-oblanceolate or oblanceolate to elliptic, and 10–40 × 5–20(–25) mm.

terminal or terminal and axillary, cymose and dichotomously or trichotomously branched, or racemose, umbellate, or capitate (subfam.
Peduncles

absent or erect, stout, 0.3–4 cm, tomentose to floccose.

Involucres

1 per node, turbinate to turbinate-campanulate, (2–)3–5 × (2–)2.5–4 mm, tomentose to floccose;

teeth 5, erect, (0.1–)0.2–0.5 mm.

Pedicels

present or absent, rarely accrescent (Brunnichia), articulate to flowers.
Flowers

(2–)2.5–5 mm;

perianth white to pinkish, glabrous;

tepals connate proximal 1/4, monomorphic, oblong;

stamens exserted, 2–5 mm;

filaments pilose proximally.

usually bisexual, sometimes bisexual and unisexual on same or different plants, rarely unisexual only, 1–many, often with stipelike base distal to articulation;

perianth persistent, often accrescent in fruit, often greenish, white, pink, yellow, red, or purple, rarely winged or keeled (Fallopia and some species of Polygonum), campanulate to urceolate, sometimes membranous, indurate (Brunnichia and Emex), or fleshy (Coccoloba, Muehlenbeckia, and some species of Persicaria) in fruit, rarely developing raised tubercles proximally (Rumex), glabrous or pubescent, sometimes glandular or glandular-punctate;

tepals 2–6, distinct or connate proximally and forming tube, usually in 2 whorls, petaloid or sepaloid, dimorphic or monomorphic, rarely coriaceous (Lastarriaea), entire, emarginate, or lobed to laciniate apically, rarely awn-tipped (Lastarriaea);

nectary a disk at base of ovary or glands associated with bases of filaments;

stamens (1–)6–9, staminode rarely present;

filaments distinct, or connate basally and sometimes forming staminal tube, free or adnate to perianth tube, glabrous or pubescent proximally;

anthers dehiscing by longitudinal slits;

pistil 1, (rudimentary pistil sometimes present in staminate flowers of monoecious or dioecious taxa), (2–)3(–4)-carpellate, homostylous (heterostylous in some species of Fagopyrum and Persicaria);

ovary 1-locular (sometimes with vestigial partitions proximally);

ovule 1, orthotropous or, rarely, anatropous, placentation basal or free-central;

styles 1–3, erect to spreading or recurved, distinct or connate proximally;

stigmas 1 per style, peltate, capitate, fimbriate, or penicillate.
Fruits

achenes, included or exserted, yellowish, brown, red, or black, homocarpic (sometimes heterocarpic in Polygonum), winged or unwinged, 2-gonous, 3-gonous, discoid, biconvex, lenticular, rarely 4-gonous or spheroidal, glabrous or pubescent.
Achenes

light brown, 3–4 mm, glabrous.

Seeds

1;

endosperm usually abundant, mealy, development nuclear;

embryo straight or curved, rarely folded.
Eriogonoideae

) tightly compact to spreading and at or just below the soil surface or spreading to erect and above the soil surface, woody;

aerial flowering stems prostrate or decumbent to erect, arising at nodes of caudex branches, at distal nodes of aerial branches, or directly from the root, slender to stout and solid or slightly to distinctly fistulose, rarely disarticulating in ringlike segments (Eriogonum).;

eriogonoideae , possibly vestigial in some perennial species of Chorizanthe) or present (subfam.; eriogonoideae );

or spikelike, racemelike, paniclelike, cymelike, or, rarely, capitate (subfam.; eriogonoideae , rarely absent in Eriogonum), glabrous or pubescent;

peduncle present or absent;

clusters of flowers subtended by involucral bracts or enclosed in typically nonmembranous tubular involucres (subfam.; eriogonoideae ) or subtended by connate bracteoles forming a persistent membranous tube (ocreola) (subfam.
Polygonoideae

), persistent or deciduous, cylindric to funnelform, sometimes 2-lobed (Polygonum), chartaceous, membranous, coriaceous or partially to entirely foliaceous;

petiole present or absent, rarely articulate basally (Fagopyrum, Polygonella, Polygonum), rarely with extrafloral nectaries (Fallopia, Muehlenbeckia);

blade simple, margins entire, occasionally crenulate, crisped, undulate, or lobed, rarely awn-tipped (Goodmania).;

polygonoideae ), comprising simple or branched clusters of compound inflorescences;

bracts absent (subfam.; polygonoideae ), or 2–10+, usually connate proximally or to 1/2 their length, rarely perfoliate, foliaceous or scalelike, margins entire, sometimes awn-tipped (subfam.; polygonoideae ).
2n

= 36.

Eriogonum racemosum

Polygonaceae
Phenology Flowering Jun–Oct.
Habitat Sandy to gravelly flats and slopes, mixed grass, sagebrush, and mountain mahogany communities, scrub oak, pinyon, juniper, and conifer woodlands
Elevation 1400-2900(-3500) m (4600-9500(-11500) ft)
Distribution
from FNA
AZ; CO; NM; NV; UT
[WildflowerSearch map]
[BONAP county map]
Widespread; well represented in the north-temperate zone
[BONAP county map]
Discussion

Eriogonum racemosum is highly variable in stature, the presence of leaflike bracts in the inflorescences, the size and shape of the leaves, and the length of the mature flowers. None of these features is geographically correlated and thus no taxonomic distinctions are attempted. The species is occasionally cultivated. The tomentose, nonfistulose flowering stems easily distinguish it from Eriogonum zionis. Individuals of E. racemosum with glabrous flowering stems are known (Reveal & Holmgren 1893, BRY, US, UTC; Goodrich 17355, BRY; Neese & White 9237, BRY), but are rare and clearly aberrant expressions.

The Navajo or Diné people use the roots of Eriogonum racemosum as a “life medicine,” primarily in the treatment of internal problems, notably poisoning and diarrhea (C. Arnold, pers. comm.; P. A. Vestal 1952). They also use it as an analgesic and orthopedic aid (D. E. Moerman 1986; L. C. Wyman and S. K. Harris 1951); there are reports of its use for venereal disease. Leaves and stems were eaten raw by the Ramah Navajo in northwestern New Mexico (Wyman and Harris).

Eriogonum racemosum is the food plant for the Spalding dotted-blue butterfly (Euphilotes spaldingi) and is occasionally visited by the desert green or Comstock’s hairstreak (Callophrys comstocki).

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

Genera 48, species ca. 1200 (35 genera, 442 species in the flora).

Monophyly of Polygonaceae is well supported by molecular studies (M. W. Chase et al. 1993; P. Cuénoud et al. 2002; A. S. Lamb Frye and K. A. Kron 2003), which place it sister to Plumbaginaceae. Wood anatomy also supports this relationship (S. Carlquist 2003). Polygonaceae has been divided variously into subfamilies (S. A. Graham and C. E. Wood Jr. 1965; K. Haraldson 1978; J. Brandbyge 1993); two often are recognized based on morphological evidence: Eriogonoideae and Polygonoideae. Recent studies using the chloroplast gene rbcL suggest Eriogonoideae are monophyletic and Polygonoideae are paraphyletic (Lamb Frye and Kron). Generic limits have been much debated, particularly the circumscription of Polygonum in the broad sense. Morphological, cytological, palynological, and anatomical data, although useful in resolving some questions about the circumscriptions and relationships of genera, have not provided a consensus regarding relationships within the family. Pollen types (J. W. Nowicke and J. J. Skvarla 1977) and chromosome numbers (Brandbyge) are diverse. Multiple base chromosome numbers have been documented in some genera, and polyploidy is common. The classification used here generally follows J. L. Reveal (1978) for Eriogonoideae and Haraldson for Polygonoideae.

A characteristic feature of the family is the ocrea, a nodal sheath variously interpreted as an outgrowth of the sheathing base of the petiole, as connate stipules, or as an expanded axillary stipule (S. A. Graham and C. E. Wood Jr. 1965). It is absent in subfamily Eriogonoideae except in some perennial, South American members of Chorizanthe, where it is rudimentary (J. L. Reveal 1978).

The flowers of Polygonaceae have been studied extensively. Most researchers concluded that six tepals is the primitive condition in the family (R. A. Laubengayer 1937), but A. S. Lamb Frye and K. A. Kron (2003) concluded that five tepals is the primitive condition, and that taxa with six or four tepals evolved multiple times within the family. The same molecular study also suggested parallel evolution of growth forms and woodiness. Floral nectaries are useful generic characters in the Polygonoideae (L.-P. Ronse Decraene and J. R. Akeroyd 1988) but their utility in floristic treatments is limited because of their small size. In some genera of Polygonaceae, the outer tepals are connate and form a slender, stipelike hypanthium base above the articulation with the true pedicel. In the Polygonoideae treatments, pedicel refers to the true pedicel plus the stipelike hypanthium above the articulation; in Eriogonoideae, stipe refers only to the stipelike hypanthium base, and pedicel is applied only to the true pedicel.

Members of the family are of relatively minor economic importance (A. N. Steward 1930; S. A. Graham and C. E. Wood Jr. 1965). Fagopyrum has been cultivated for millennia, Coccoloba produce edible fruits, and the petioles of Rheum and leaves of some species of Rumex are edible. Many species have been used as food or medicine or for ceremonies by various tribes of Native Americans. Outside the flora area, the family includes some tropical trees harvested for timber (Coccoloba and Triplaris). Some species of Fallopia, Persicaria, Polygonum, and Rumex are cosmopolitan weeds, and Emex is a pernicious weed in parts of the world. Of the 35 genera in the flora, four are entirely non-native: Emex, Fagopyrum, Muehlenbeckia, and Rheum. Antigonon and Coccoloba are popular ornamentals in the southern part of the flora region. Many species of Eriogonum are planted in rock gardens. Persicaria species are important wetland plants because waterfowl consume their fruits.

Mechanisms for achene dispersal vary greatly. Hooked or awned involucres occur in many genera of subfam. Eriogonoideae. The outer tepals of the perianth expand into wings (Fallopia) or spines (Emex), or the achene has wings (Eriogonum alatum, Oxyria, Rheum, and Rumex), which aid in dispersal by wind or water. The achenes are forcibly tossed from the plant in Persicaria virginiana, and persistent, hooked styles aid in their transport by animals. In Coccoloba, the fleshy tube of the tepals aids in dispersal by birds.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Ocreae absent; nodes not swollen; flowers usually enclosed in involucres or subtended byinvolucral bracts, these rarely absent (in Gilmania)
Polygonaceae subfam. Eriogonoideae
1. Ocreae present, persistent or deciduous; nodes usually swollen; flowers not enclosed in involucres or associated with involucral bracts
Polygonaceae subfam. Polygonoideae
Source FNA vol. 5, p. 295. FNA vol. 5, p. 216. Authors: Craig C. Freeman, James L. Reveal.
Parent taxa 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. 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. racemosum var. obtusum, E. racemosum var. orthocladon
Name authority Nuttall: Proc. Acad. Nat. Sci. Philadelphia 4: 14. (1848) Jussieu
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora

The species comparison tool is brought to you by:
Northwest Wildflowers