Eriogonum evanidum

Reveal

Phytologia 86: 132. 2004.

Common names: Vanishing wild buckwheat
Treatment appears in FNA Volume 5. Treatment on page 427. Mentioned on page 416.

Herbs, erect, 1–2 dm, tomentose to floccose, grayish. Stems: aerial flowering-stems erect, 0.3–0.6 dm, tomentose to floccose. Leaves basal; petiole 0.5–1.5 cm, tomentose; blade broadly ovate to orbiculate or reniform, 0.7–1.2 × 0.7–1.2 cm, densely white-tomentose abaxially, floccose and greenish adaxially. Inflorescences narrowly cymose, infrequently distally uniparous due to suppression of secondary branches, open, 5–15 × 5–10 cm; branches tomentose to floccose; bracts 0.5–2 × 0.5–1 mm. Peduncles absent. Involucres somewhat appressed to branches, campanulate, 1–2 × 1–2 mm, glabrous; teeth 5, spreading, 0.4–0.8 mm. Flowers 0.8–1.2 mm; perianth ochroleucous, glabrous; tepals dimorphic, those of outer whorl ovate, slightly hastate proximally in fruit, those of inner whorl lanceolate to elliptic; stamens included, 0.4–0.6 mm; filaments glabrous. Achenes dark-brown, 3-gonous, 1.3–1.5 mm.


Phenology: Flowering Jul–Oct.
Habitat: Sandy to gravelly flats and slopes, sagebrush communities, oak and montane conifer woodlands
Elevation: 1100-2100 m

Distribution

V5 890-distribution-map.gif

Calif., Mexico (Baja California)

Discussion

Of conservation concern.

Eriogonum evanidum is presumed extinct. The last known collections were made in Bear Valley in the San Bernardino Mountains, San Bernardino County, in 1931 (Templeton 1588, BRY, KANS, NY); Hemet Valley in the San Jacinto Mountains, Riverside County (Ziegler s.n., 10 Oct 1967, GH, RSA, UC, UTC); and the Pine Valley area, San Diego County, in 1938. It is related to two sprawling annual Mexican species with mostly elliptic basal leaf blades: E. foliosum S. Watson, with weakly hastate cauline leaves, and E. hastatum Wiggins, with strongly hastate cauline leaves.

Selected References

None.

Lower Taxa

None.

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

... more about "Eriogonum evanidum"
included +  and exserted +
3-gonous +
usually red +  and cream or yellow +
oblong +  and ellipsoid or oval +
James L. Reveal +
Reveal +
deciduous +  and persistent +
stipelike +  and acute +
Eriogonum sect. Oregonium +
awn-tipped +  and simple +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
floccose +  and white-tomentose +
broadly ovate;orbiculate or reniform +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
not awn-tipped +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
glandular +, pubescent +  and glabrous +
scale-like +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
grooved +, disarticulating +  and dichotomous +
not brittle +
tomentose +  and floccose +
scabrellous +
ridged +, angled +  and round +
spreading +  and erect +
whorled +, opposite +  and alternate +
Vanishing wild buckwheat +
Calif. +  and Mexico (Baja California) +
1100-2100 m +
unisexual +, , +  and bisexual +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
not disarticulating +  and solid +
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 +
Sandy to gravelly flats and slopes, sagebrush communities, oak and montane conifer woodlands +
open +, uniparous +  and cymose +
capitate +  and subcapitate +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
cymelike +, paniclelike +, racemelike +  and spikelike +
5 cm50 mm <br />0.05 m <br /> (10 cm100 mm <br />0.1 m <br />) +
connate +  and free +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
campanulate +
nonmembranous +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
in whorls +, opposite +, alternate +  and rosulate +
marcescent +
persistent +
bractlike +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
not swollen +
orthotropous +
accrescent +
erect to deflexed +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Flowering Jul–Oct. +
homostylous +  and 3-carpellate +
, +  and solid +
slender;stout +
persistent +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
decumbent to erect +  and prostrate +
erect +, ascending +  and prostrate +
short-pilose +, puberulent +, sericeous +, glabrous +, floccose +, tomentose +  and lanate +
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 evanidum +
Eriogonum subg. Oregonium +
species +
emarginate +  and entire +
1/4 +  and 1/2 +
lobed +  and laciniate +
coriaceous +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
involucral +
persistent +
membranous +
pubescent +  and glabrous +
short-pilose +, puberulent +, sericeous +, floccose +  and tomentose or lanate +
annual +, biennial +  and perennial +
tomentose +  and floccose +
synoecious +, monocarpic +, polycarpic +  and , +
3 +, 2 +  and 1 +