Eriogonum heermannii var. argense

(M. E. Jones) Munz

Aliso 4: 89. 1958.

Common names: Heermann’s rough wild buckwheat
Endemic
Basionym: Eriogonum sulcatum var. argense M. E. Jones Contr. W. Bot. 11: 15. 1903
Synonyms: Eriogonum apachense Reveal Eriogonum heermannii subsp. argense (M. E. Jones) Munz Eriogonum heermannii var. subracemosum (S. Stokes) Reveal Eriogonum howellii Eriogonum howellii var. subracemosum S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 307. Mentioned on page 304, 305, 306.

Shrubs, spreading to rounded, sparsely to densely branched, 1–10 × 2–10 (–12) dm. Leaf-blades linear to linear-lanceolate or oblanceolate to elliptic or oblong, 0.5–1.2 (–1.5) × 0.1–0.6 cm, tomentose or glabrous abaxially. Inflorescences (1–) 3–20 × (1–) 3–25 cm; branches diffuse with racemosely arranged involucres at tips, slender to stout, round, smooth, glabrous, scabrellous, or infrequently papillate-scabrous, infrequently somewhat spinose. Involucres narrowly turbinate to campanulate, 0.9–1.8 × 0.7–1.3 mm. Flowers 1.5–4 mm; perianth white to yellowish white or reddish.


Phenology: Flowering Apr–Nov.
Habitat: Limestone (rarely volcanic) cliffs, outcrops, and washes, or on gypsophilous outcrops, saltbush, blackbrush, sagebrush, and mountain mahogany communities, pinyon-juniper and montane conifer woodlands
Elevation: 800-2800 m

Discussion

Variety argense is widespread and occasionally locally common. It is found in the Mohave Desert from Inyo County south through San Bernardino County to northern Riverside County, California, then eastward across Nevada in northern Clark, Esmeralda, Lincoln, Nye, and White Pine counties, into Coconino, Mohave, Navajo counties, Arizona. It just enters the Sonoran Desert in Yavapai County, Arizona, and is disjunct farther to the east in Graham and Gila counties. A population near Vail (Gila County) sampled by M. E. Jones in 1903 (DS, POM, US) has not been rediscovered, although the variety is known from Pueblo Canyon in the Sierra Ancha (Wagner 320, DUKE).

The scabrellous condition of the inflorescence branches of this variety can be obscure, occasionally leading to its misidentification as var. heermannii. The flowering stems and inflorescence branches are always rounded, not angled or ribbed as in var. sulcatum, but the latter condition is sometimes difficult to see, resulting in plants of that variety being misidentified as var. argense. Specimens from above the Little Colorado River, and along the Colorado River near the mouth of the Little Colorado, with stout, often pointed branches have been distinguished as var. subracemosum. They are low, spreading, and usually sparsely branched, unlike the typical expressions of var. argense. Based on herbarium specimens, it appears that var. subracemosum merges completely with classical var. argense on the cliff faces above the Colorado River on and to the east of the Kaibab Plateau. The disjunct Eriogonum apachense of gypsophilous outcrops northwest of Bylas in Graham County, Arizona, differs little from plants found on limestone ledges and slopes in the White Hills of Yavapai County. By and large, the involucres of typical E. apachense are narrowly turbinate, the leaf blades remain tomentose on the abaxial surface, and the inflorescence branches are decidedly more slender. The reduction of E. apachense seems justified, resulting in a var. argense that is highly variable but nonetheless easy to distinguish.

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.

light-brown;brown +
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) Munz +
deciduous +  and persistent +
stipelike +
Eriogonum sulcatum var. argense +
papillate +
awn-tipped +  and simple +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
tomentose +  and floccose or glabrous abaxially +
oblong;elliptic;spatulate;oblanceolate;oblong;elliptic;spatulate;oblanceolate;linear +
0.1 cm1 mm <br />0.001 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
not awn-tipped +
leaflike +  and semileaflike +
glandular +, pubescent +  and glabrous +
scale-like +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
grooved +  and dichotomous +
not brittle +
spreading +  and erect +
papillate-scabrous +  and scabrellous +
spreading +  and erect +
whorled +, opposite +  and alternate +
Heermann’s rough wild buckwheat +
Ariz. +, Calif. +  and Nev. +
800-2800 m +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
unisexual +, , +  and bisexual +
not attenuate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
decumbent to erect +  and prostrate +
not fistulose +
slender;stout +
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 +
Limestone (rarely volcanic) cliffs, outcrops, and washes, or on gypsophilous outcrops, saltbush, blackbrush, sagebrush, and mountain mahogany communities, pinyon-juniper and montane conifer woodlands +
reduced +
capitate +  and subcapitate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
dense +  and diffuse +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
cymelike +, paniclelike +, racemelike +  and spikelike +
3 cm30 mm <br />0.03 m <br /> (25 cm250 mm <br />0.25 m <br />) +
connate +  and free +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
floccose +  and glabrous +
narrowly turbinate +  and campanulate +
nonmembranous +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
glabrous +  and tomentose +
linear +  and linear-lanceolate or oblanceolate +
0.1cm;0.6cm +
in whorls +, opposite +, alternate +  and rosulate +
deciduous +
bractlike +
pubescent +  and glabrous +
not swollen +
orthotropous +
accrescent +
curved +  and straight +
erect to deflexed +
white;yellowish white or reddish +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
glabrous +  and floccose +
0.1 cm1 mm <br />0.001 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Flowering Apr–Nov. +
homostylous +  and 3-carpellate +
, +  and solid +
slender;stout +
persistent +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
decumbent to erect +  and prostrate +
erect +  and spreading +
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 apachense +, Eriogonum heermannii subsp. argense +, Eriogonum heermannii var. subracemosum +, Eriogonum howellii +  and Eriogonum howellii var. subracemosum +
chambered +  and solid +
slender +  and stout +
Eriogonum heermannii var. argense +
Eriogonum heermannii +
variety +
emarginate +  and entire +
in proximal 1/2 +  and connate +
0 +  and 1/2 +
lobed +  and laciniate +
coriaceous +
slender;stout +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
persistent +
membranous +
pubescent +  and glabrous +
grayish +  and greenish +
floccose +  and glabrous +
synoecious +, monocarpic +, polycarpic +  and , +
3 +, 2 +  and 1 +