Eriogonum umbellatum var. polyanthum

(Bentham) M. E. Jones

Contr. W. Bot. 11: 5. 1903.

Common names: American River sulphur flower
Endemic
Basionym: Eriogonum polyanthum Bentham in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 12. 1856
Synonyms: Eriogonum umbellatum subsp. polyanthum (Bentham) S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 351. Mentioned on page 336, 342, 343, 352.

Shrubs, round, rather open, 4–10 × 5–10 dm. Aerial flowering-stems erect, 1–2 dm, floccose, without one or more leaflike bracts ca. midlength. Leaves in rather open, terminal rosettes; blade oblanceolate to narrowly elliptic, 1–3 × 0.3–1 (–1.3) cm, densely white-tomentose abaxially, thinly floccose or glabrous and light green adaxially, margins plane. Inflorescences umbellate or compound-umbellate, branched 1–2 (–3) times; branches thinly floccose or glabrous, occasionally central branch seemingly with a whorl of bracts ca. midlength; involucral tubes 2.5–4 mm, floccose, lobes 2–3.5 mm. Flowers 4–7 mm; perianth bright-yellow.


Phenology: Flowering Jun–Sep.
Habitat: Serpentine flats and slopes, oak and montane conifer woodlands
Elevation: 800-1500 m

Discussion

The inflorescences of var. polyanthum are commonly compound-umbellate, but plants with reduced yet bracteated inflorescences do occur. Those with a reduced inflorescence technically consist of a long (6–10 cm), central, bractless peduncle and two lateral branches (3–4 cm), with each of the latter bearing a peduncle (3–6 cm). Such branches seem to have a whorl of leaflike bracts, but actually the bracts are positioned between the branch and involucres (technically at the base of the peduncle) and thus are like other members of the genus.

The name var. polyanthum has been misapplied in California to plants here attributed to var. modocense and var. dumosum.

Selected References

None.

Lower Taxa

None.

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

light-brown;brown +
included +  and exserted +
3-gonous +
usually red +  and cream or yellow +
oblong +  and ellipsoid or oval +
James L. Reveal +
(Bentham) M. E. Jones +
deciduous +  and persistent +
stipelike +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Eriogonum polyanthum +
awn-tipped +  and simple +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
light green +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
glabrous +, floccose +  and white-tomentose +
oblanceolate;narrowly elliptic +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not awn-tipped +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
midlength +
glandular +, pubescent +  and glabrous +
3;several +
scale-like +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
grooved +, disarticulating +  and dichotomous +
not brittle +
glabrous +  and floccose +
scabrellous +
spreading +  and erect +
whorled +, opposite +  and alternate +
American River sulphur flower +
800-1500 m +
curved +  and straight +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
unisexual +  and bisexual +
attenuate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 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 +
Serpentine flats and slopes, oak and montane conifer woodlands +
1-2(-3) times +
branched +, compound-umbellate +  and umbellate +
capitate +  and subcapitate +
3 cm30 mm <br />0.03 m <br /> (25 cm250 mm <br />0.25 m <br />) +
cymelike +, paniclelike +, racemelike +  and spikelike +
2 cm20 mm <br />0.02 m <br /> (18 cm180 mm <br />0.18 m <br />) +
connate +  and free +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
tomentose +  and thinly floccose or glabrous +
turbinate +  and campanulate +
nonmembranous +
0.15 cm1.5 mm <br />0.0015 m <br /> (1 cm10 mm <br />0.01 m <br />) +
in whorls +, opposite +, alternate +  and rosulate +
persistent +
cauline +  and basal +
bractlike +
pubescent +  and glabrous +
not swollen +
orthotropous +
accrescent +
curved +  and straight +
erect to deflexed +
bright-yellow +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
mostly tomentose +  and floccose or glabrous +
0.1 cm1 mm <br />0.001 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering Jun–Sep. +
homostylous +  and 3-carpellate +
0.3 cm3 mm <br />0.003 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
Contr. W. Bot. +
, +  and solid +
slender;stout +
persistent +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 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 umbellatum subsp. polyanthum +
chambered +  and solid +
slender +  and stout +
Eriogonum umbellatum var. polyanthum +
Eriogonum umbellatum +
variety +
emarginate +  and entire +
1/4 +  and 1/3 +
usually spatulate +  and obovate +
coriaceous +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
involucral +
persistent +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
pubescent +  and glabrous +
sericeous +, lanate +  and tomentose floccose or glabrous +
dioecious +, polygamodioecious +, synoecious +  and polycarpic +
annual +, biennial +  and perennial +
tomentose +  and glabrous +
midlength +
3 +, 2 +  and 1 +