Eriogonum thymoides |
Eriogonum racemosum |
|
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thyme buckwheat, thyme wild buckwheat, thyme-leaf buckwheat, thyme-leaf wild buckwheat |
red-root wild buckwheat, redroot buckwheat |
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Habit | Subshrubs, spreading, polygamodioecious, 0.5–2(–3) × 1–3(–4) dm, tomentose to sericeous. | Herbs, erect to slightly spreading, 3–8(–10) × 0.5–1.5 dm, tomen-tose to floccose or rarely glabrous, grayish. |
Stems | caudex spreading; aerial flowering stems 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(–1.2) dm, tomentose to sericeous, with a whorl of 6–10(–12), leaflike bracts ca. midlength, these similar to leaf blades, 0.3–0.8(–1) × 0.1–0.2 cm. |
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. |
Leaves | in compact basal rosettes, fasciculate, and sheathing up stems; petiole 0.05–0.2 cm; blade linear to narrowly spatulate, (0.2–)0.3–1(–1.5) × 0.1–0.2(–0.3) cm, densely white-tomentose abaxially, silky-villous or sericeous adaxially, margins entire, inrolled to tightly revolute. |
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. |
Inflorescences | capitate, 0.8–2 cm wide; branches absent; bracts absent immediately below involucre. |
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. |
Peduncles | absent or erect, stout, 0.3–4 cm, tomentose to floccose. |
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Involucres | 1 per node, turbinate, 3–5 × 2.5–4 mm, villous to sericeous; teeth 6–8, erect, 0.5–1 mm. |
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. |
Flowers | 4–10 mm, including 0.5–1 mm stipelike base; perianth white to pale yellow or yellow, becoming pink to rose, villous abaxially; tepals monomorphic, obovate; stamens included to slightly exserted, 2–4 mm; filaments pilose proximally. |
(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. |
Achenes | light brown, 2–2.5 mm, glabrous except for densely pubescent beak. |
light brown, 3–4 mm, glabrous. |
2n | = 36. |
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Eriogonum thymoides |
Eriogonum racemosum |
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Phenology | Flowering Apr–Jul. | Flowering Jun–Oct. |
Habitat | Sandy to gravelly, often volcanic flats, slopes, and outcrops, mixed grassland and sagebrush communities, montane conifer woodlands | Sandy to gravelly flats and slopes, mixed grass, sagebrush, and mountain mahogany communities, scrub oak, pinyon, juniper, and conifer woodlands |
Elevation | (200-)600-1700 m ((700-)2000-5600 ft) | 1400-2900(-3500) m (4600-9500(-11500) ft) |
Distribution |
ID; OR; WA
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AZ; CO; NM; NV; UT
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Discussion | Eriogonum thymoides is an exquisite species concentrated in three regions of the Pacific Northwest. The first is along the eastern edge of the Cascade Range from near Wenatchee, Washington (Adams, Benton, Chelan, Douglas, Franklin, Grant, Kittitas, Klickitat, Lincoln, and Yakima counties), to near the Dalles in extreme north-central Oregon (Union County). The second is from Baker and northern Malheur counties, Oregon, to Adams, Canyon, and Washington counties, Idaho. A third series of populations is in the Mount Bennett Hills area of Gooding County, Idaho, and just over the borders in Blaine, Camas, Elmore, and Lincoln counties. Staminate plants tend to have yellow flowers that quickly fade after pollen release. Pistillate plants tend to have white to pale yellow flowers that persist and greatly elongate as the achene matures. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 5, p. 360. | FNA vol. 5, p. 295. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla |
Sibling taxa | ||
Synonyms | E. sphaerocephalum subsp. minimum, E. thymoides subsp. congestum | E. racemosum var. obtusum, E. racemosum var. orthocladon |
Name authority | Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 9. (1856) | Nuttall: Proc. Acad. Nat. Sci. Philadelphia 4: 14. (1848) |
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