Eriogonum arcuatum

Greene

Pittonia 4: 319. 1901.

Endemic
Synonyms: Eriogonum jamesii var. arcuatum (Greene) S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 369. Mentioned on page 333, 368, 370.

Herbs, spreading to often compact mats, 0.2–2.5 × 2–10 dm, floccose. Stems: caudex absent or spreading; aerial flowering-stems erect or nearly so, slender, solid, not fistulose, usually arising directly from a taproot, 0.2–2 dm, floccose. Leaves basal, typically not in rosettes; petiole 0.5–2 cm, tomentose to floccose; blade oblanceolate or oblong to elliptic, 0.5–3 × 0.5–1.5 cm, densely tomentose abaxially, mostly floccose and grayish or greenish adaxially, margins entire, plane. Inflorescences umbellate or compound-umbellate, occasionally capitate or even reduced to single involucre, 0.3–2 × 0.3–2 dm; branches floccose; bracts 3–8, semileaflike at proximal node, 0.3–2 × 0.2–1 cm, often scalelike distally. Involucres 1 per node, usually campanulate, 3–7 × 3–8 mm, floccose; teeth 5–8, erect, 0.1–0.5 mm. Flowers 4–8 mm, including 0.7–2 mm stipelike base; perianth yellow, densely pubescent abaxially; tepals dimorphic, those of outer whorl lanceolate to elliptic, 1.5–5 × 1–3 mm, those of inner whorl lanceolate to fan-shaped, 1.5–7 × 2–4 mm; stamens exserted, 2–4 mm; filaments pilose proximally. Achenes light-brown to brown, 4–5 mm, glabrous except for sparsely pubescent beak.

Distribution

V5 757-distribution-map.gif

Ariz., Colo., N.Mex., Utah, Wyo.

Discussion

Varieties 3 (3 in the flora).

Eriogonum arcuatum has long been included under E. jamesii, primarily as the var. flavescens. It has also gone under the name E. bakeri, published by Greene about six weeks after he published E. arcuatum; the Fort Collins, Colorado, entomologist and botanist Charles Fuller Baker collected the types of both.

Selected References

None.

Key

1 Involucres (3-)4-8 mm wide; inflorescences umbellate or compound-umbellate, rarely capitate; flowers (4-)5-8 mm; below 3000 m; n Arizona, c and w Colorado, nw New Mexico, e Utah, se Wyoming Eriogonum arcuatum var. arcuatum
1 Involucres 3-5 mm wide; inflorescences capitate, rarely umbellate or reduced to single involucre; flowers 4-5(-6) mm or 6-7 mm; usually above 3000 m in c Colorado, or 1600-1900 m in sw Utah > 2
2 Flowers 4-5(-6) mm; Zion National Park, Utah Eriogonum arcuatum var. rupicola
2 Flowers 6-7 mm; Rocky Mountains, Colorado Eriogonum arcuatum var. xanthum

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... more about "Eriogonum arcuatum"
light-brown;brown +
included +  and exserted +
3-gonous +
usually red +  and cream or yellow +
oblong +  and ellipsoid or oval +
James L. Reveal +
Greene +
deciduous +  and persistent +
stipelike +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
awn-tipped +  and simple +
greenish +  and grayish +
0.5 cm5 mm <br />0.005 m <br /> (3 cm30 mm <br />0.03 m <br />) +
floccose +  and tomentose +
oblong;elliptic +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
not awn-tipped +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
glandular +, pubescent +  and glabrous +
scale-like +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
grooved +, disarticulating +  and dichotomous +
not brittle +
scabrellous +
spreading +  and erect +
whorled +, opposite +  and alternate +
Ariz. +, Colo. +, N.Mex. +, Utah +  and Wyo. +
curved +  and straight +
unisexual +  and bisexual +
attenuate +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
decumbent to erect +  and prostrate +
not fistulose +
unwinged +  and winged +
black +, red +, brown +  and yellowish +
exserted +  and included +
pubescent +  and glabrous +
spheroidal +, 4-gonous +, lenticular +, biconvex +, discoid +, 3-gonous +  and 2-gonous +
compound-umbellate +  and umbellate +
cymelike +, paniclelike +, racemelike +  and spikelike +
connate +  and free +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
campanulate +
nonmembranous +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
in whorls +, opposite +, alternate +  and rosulate +
persistent +
bractlike +
pubescent +  and glabrous +
not swollen +
orthotropous +
accrescent +
curved +  and straight +
erect to deflexed +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
tomentose +  and floccose +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
homostylous +  and 3-carpellate +
, +  and solid +
slender;stout +
persistent +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
decumbent to erect +  and prostrate +
prostrate +  and erect +
glandular +, pubescent +  and glabrous +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
consisting of a series +  and tubular +
distinct +
erect;spreading or recurved +
spreading;erect +
Eriogonum jamesii var. arcuatum +
chambered +  and solid +
slender +  and stout +
Eriogonum arcuatum +
Eriogonum subg. Oligogonum +
species +
emarginate +  and entire +
1/4 +  and 1/3 +
lobed +  and laciniate +
coriaceous +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
persistent +
membranous +
pubescent +  and glabrous +
sericeous +, lanate +  and tomentose floccose or glabrous +
dioecious +, polygamodioecious +, synoecious +  and polycarpic +
annual +, biennial +  and perennial +
synoecious +, monocarpic +, polycarpic +  and , +
3 +, 2 +  and 1 +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +