Eriogonum microthecum var. ambiguum

(M. E. Jones) Reveal in P. A. Munz

in P. A. Munz, Suppl. Calif. Fl., 61. 1968.

Common names: Yellow-flowered wild buckwheat
Endemic
Basionym: Eriogonum aureum var. ambiguum M. E. Jones Proc. Calif. Acad. Sci., ser. 2, 5: 719. 1895
Treatment appears in FNA Volume 5. Treatment on page 247. Mentioned on page 243.
Revision as of 09:29, 30 July 2020 by imported>Volume Importer
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Subshrubs or shrubs, 0.5–5 × 1–8 dm. Stems: caudex absent; aerial flowering-stems 0.2–1 dm, mostly floccose. Leaves: blade 0.8–2.5 × (0.2–) 0.3–0.6 (–0.8) cm, densely white or reddish-brown-tomentose abaxially, floccose adaxially, margins rarely revolute. Inflorescences 1–5 (–12) cm; branches tomentose to floccose. Involucres 2–2.5 mm, tomentose to floccose. Flowers (1.5–) 2–2.5 (–3) mm; perianth yellow. Achenes 1.5–2 mm.


Phenology: Flowering Jul–Sep.
Habitat: Sandy to rocky soil, sagebrush and saltbush communities, pinyon-juniper and conifer woodlands
Elevation: (1100-)1900-3300 m

Distribution

V5 458-distribution-map.gif

Calif., Idaho, Nev., Oreg.

Discussion

Variety ambiguum occurs in eastern California, northwestern Nevada, and southeastern Oregon. In portions of its range, var. ambiguum appears to be little more than a yellow-flowered phase of var. laxiflorum. However, where the two occur together, intermediates are rarely found, and limited garden studies indicate that flower color is genetically fixed. Nonflowering specimens from southern Owyhee County, Idaho, have been tentatively assigned to this taxon.

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

included +  and exserted +
3-gonous +
usually red +  and cream or yellow +
oblong +  and ellipsoid or oval +
acute;obtuse or rounded +
James L. Reveal +
(M. E. Jones) Reveal in P. A. Munz +
deciduous +  and persistent +
stipelike +
Eriogonum aureum var. ambiguum +
papillate +
awn-tipped +  and simple +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
floccose +  and reddish-brown-tomentose +
linear;obovate +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
not awn-tipped +
leaflike +  and semileaflike +
glandular +, pubescent +  and glabrous +
linear +  and triangular +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
gray +, green +, reddish-tomentose to floccose or glabrate +  and brownish +
not brittle +
spreading +  and erect +
tomentose +  and floccose +
scabrellous +
ridged +, angled +  and round +
whorled +, opposite +  and alternate +
Yellow-flowered wild buckwheat +
Calif. +, Idaho +, Nev. +  and Oreg. +
(1100-)1900-3300 m +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
unisexual +, , +  and bisexual +
not attenuate +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 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 +
Sandy to rocky soil, sagebrush and saltbush communities, pinyon-juniper and conifer woodlands +
reduced +
capitate +  and subcapitate +
6 cm60 mm <br />0.06 m <br /> (12 cm120 mm <br />0.12 m <br />) +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
10 cm100 mm <br />0.1 m <br /> (13 cm130 mm <br />0.13 m <br />) +
dense +  and diffuse +
0.5 cm5 mm <br />0.005 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
connate +  and free +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
tomentose +  and floccose +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
nonmembranous +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
in whorls +, opposite +, alternate +  and rosulate +
persistent +
bractlike +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
not swollen +
orthotropous +
accrescent +
curved +  and straight +
tomentose;floccose +
erect to deflexed +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
tomentose +  and floccose or glabrous +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering Jul–Sep. +
homostylous +  and 3-carpellate +
in P. A. Munz, Suppl. Calif. Fl., +
, +  and solid +
slender;stout +
persistent +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
decumbent to erect +  and prostrate +
spreading +  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 +
chambered +  and solid +
slender +  and stout +
Eriogonum microthecum var. ambiguum +
Eriogonum microthecum +
variety +
emarginate +  and entire +
0 +  and 1/2 +
1/5 +  and 2/5 +
oblong +  and obovate +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
persistent +
membranous +
pubescent +  and glabrous +
shrub +  and subshrub +
glabrous +, floccose +  and tannish-tomentose +
synoecious +, monocarpic +, polycarpic +  and , +
3 +, 2 +  and 1 +