Eriogonum lobbii |
Eriogonum exaltatum |
|
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granite buckwheat, granite wild buckwheat, Lobb's buckwheat, Lobb's wild buckwheat |
ladder buckwheat, ladder wild buckwheat |
|
Habit | Herbs, compact or sprawling, matted, 0.3–3 × 1–2.5 dm, tomentose to floccose. | Herbs, erect, annual, (0.5–)3–6(–10) dm, glabrous, glaucous, grayish. |
Stems | caudex absent or nearly so; aerial flowering stems prostrate to decumbent or weakly erect, slender or stout, solid, not fistulose, usually arising directly from a taproot, 0.5–1.5(–2) dm, tomentose to floccose. |
caudex absent; aerial flowering stems erect, solid, not fistulose, (0.5–)1–2 dm, glabrous. |
Leaves | basal, in well-defined rosettes; petiole (0.8–)1–3.5(–5) cm, tomentose to floccose; blade ovate to obovate or round-oval, 1–4(–5) × 1–4(–5) cm, densely white- to grayish- or reddish-tomentose abaxially, less so to floccose or glabrous and greenish adaxially, margins entire, plane. |
basal; petiole 1–10 cm, tomentose; blade sub-cordate to orbiculate, (1.5–)2–5(–8) × (1.5–)2–5(–8) cm, densely white-tomentose abaxially, floccose to subglabrous and green adaxially, margins often wavy. |
Inflorescences | subcapitate to umbellate or infrequently 2-umbellate, 1–4 × 1–4 cm; branches tomentose to floccose; bracts 3–5 at proximal node, leaflike, 0.6–1.5(–2.5) × 0.1–0.5(–0.8) cm, sometimes absent immediately below involucre. |
cymose, spreading when immature, quickly becoming narrowly erect and strict with whiplike branches, (5–)10–50(–80) × 10–50 cm; branches glabrous, glaucous; bracts 3, scalelike, 1–1.5(–2) × 0.4–1 mm. |
Peduncles | absent or erect, straight, slender, 0.1–0.2 cm, glabrous. |
|
Involucres | 1 per node, turbinate-campanulate to campanulate, 5–10(–12) × 5–10(–12) mm, thinly tomentose to lanate; teeth 6–10, usually lobelike, mostly reflexed, 2–6 mm. |
turbinate, 2–2.5(–3) × 1.5–2.5 mm, glabrous; teeth 5, erect, 0.5–1.5 mm. |
Flowers | 5–7 mm, including 0.1–0.4 mm stipelike base; perianth white to rose, glabrous; tepals monomorphic, oblong-obovate; stamens exserted, 5–7 mm; filaments pilose proximally. |
1.5–2 mm; perianth white with green or reddish midribs, becoming pinkish, glabrous; tepals dimorphic, those of outer whorl oblong, those of inner whorl lanceolate; stamens exserted, 1.5–2.5 mm; filaments pilose proximally. |
Achenes | light brown to brown, 4.5–6 mm, glabrous. |
dark brown to blackish, 3-gonous, 2–2.5 mm, glabrous. |
2n | = 40. |
= 40. |
Eriogonum lobbii |
Eriogonum exaltatum |
|
Phenology | Flowering Jun–Aug. | Flowering May–Oct. |
Habitat | Gravelly to rocky or talus slopes, mixed grassland, buckbrush, manzanita, and sagebrush communities, montane, subalpine, or alpine conifer woodlands | Sandy to gravelly flats and slopes, saltbush, creosote bush, greasewood, blackbrush, and mesquite communities, rarely in pinyon-juniper woodlands |
Elevation | (1000-)1600-3800 m ((3300-)5200-12500 ft) | 500-1400 m (1600-4600 ft) |
Distribution |
CA; NV; OR
|
AZ; CA; NV; UT |
Discussion | Eriogonum lobbii is rather infrequent throughout its range. It is found in three widely scattered areas of concentration: the high mountains of northwestern California and southwestern Oregon; the southern portion of the North Coast Range of California; and the Sierra Nevada of eastern California and west-central Nevada. In the first two areas, the plants frequently are associated with serpentine soils; elsewhere the species is found almost exclusively on granitic soils and infrequently on volcanic ones. There are some morphologic differences between the Sierran plants and those of the coastal mountains, but no taxonomic separation is suggested. The species is a food plant for the intermediate dotted-blue butterfly (Euphilotes intermedia). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum insigne has been a troublesome taxon. The type, collected by E. Palmer in 1876, is a curious specimen from near Paragonah in Iron County, Utah. That expression has not been recollected and, after another frustrating review of the type material, it is now referred to E. deflexum, along with other odd specimens from southern Nevada and California that have always been difficult to assign. As a result, the tall, upright plants with long, whiplike branches of northwestern Arizona (Mohave County), southern Nevada (northeastern Clark and southern Lincoln counties), and southwestern Utah (southwestern Washington County), are now recognized under the name E. exaltatum. Some specimens remain problematic. Immature plants of E. exaltatum (Goodding 2302, GH, MIN, MO, NY, RM, UC) resemble E. bifurcatum. Specimens from Eureka Valley (DeDecker 4741, NY) and western Pahrump Valley (Abrams 14248, DS, GH, NY) in Inyo County, California, appear to belong to E. exaltatum. Like Eriogonum exaltatum, some populations of E. deflexum var. deflexum have nearly erect involucres. The plants from the Buried Hills (Nye and Clark counties, Nevada) are particularly odd. Single plants from a few collections in Kane County, Utah, have sessile, seemingly erect involucres in the forks of inflorescence branches. None of these plants has the characteristic long, whiplike branches of E. exaltatum, and they are not included in E. deflexum var. deflexum. The type of E. deflexum var. rectum from San Bernardino County, California (Reveal & Broome 6385, CAS, NY, US, etc.), has individual specimens with both deflexed and somewhat erect involucres, along with whiplike branches. Collections from Imperial and San Diego counties, previously associated with what is here termed E. exaltatum, are now considered specimens of E. deflexum. Clearly, more work is required to understand these species fully. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 374. | FNA vol. 5, p. 397. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma |
Sibling taxa | ||
Name authority | Torrey & A. Gray: Proc. Amer. Acad. Arts 8: 162. (1870) | M. E. Jones: Contr. W. Bot. 15: 61. (1929) |
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