Eriogonum arborescens

Greene

Bull. Calif. Acad. Sci. 1: 11. 1884.

Common names: Santa Cruz Island wild buckwheat
Endemic
Treatment appears in FNA Volume 5. Treatment on page 302. Mentioned on page 227, 301.

Shrubs, erect to spreading, 6–15 (–20) × 5–30 dm, glabrous and cinereous, reddish. Stems spreading to erect, occasionally with persistent leaf-bases, up to 3/4 or more height of plant; caudex stems absent; aerial flowering-stems erect, stout, solid, not fistulose, 0.5–1 (–1.5) dm, glabrous. Leaves cauline, 1 per node; petiole 0.1–0.5 cm, tomentose; blade linear to narrowly oblong, 2–4 (–5) × 0.1–0.4 (–0.6) cm, white-tomentose abaxially, cinereous to glabrate and greenish adaxially, margins often revolute. Inflorescences cymose, 5–10 × 5–15 (–20) cm; branches dichotomous, glabrous; bracts 1–3, leaflike, lanceolate to oblong, 0.5–2 × 0.3–1.5 cm. Peduncles absent or erect, stout, 0.1–0.5 cm, cinereous. Involucres 1 per node, campanulate, 2–3 × 2.5–4 mm, cinereous; teeth 5–7, erect, 0.5–1.5 mm. Flowers 2–3.5 (–4) mm; perianth white to pinkish, villous abaxially; tepals connate proximally, monomorphic, oblanceolate to narrowly obovate; stamens exserted, 3–5 mm; filaments glabrous. Achenes brown, 2.5–3.5 mm, glabrous. 2n = 40.


Phenology: Flowering Apr–Oct.
Habitat: Rocky slopes and canyon walls, coastal scrub communities
Elevation: 10-600 m

Discussion

Of conservation concern.

Eriogonum arborescens is local and occasionally rare on Santa Cruz, Santa Rosa, and Anacapa islands in Santa Cruz and Ventura counties. The species is cultivated, and populations have become naturalized on the mainland from San Mateo County south to San Diego, in large part because of planting along highways. Every effort should be made to remove these naturalized populations from the mainland.

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.

... more about "Eriogonum arborescens"
included +  and exserted +
3-gonous +
usually red +  and cream or yellow +
oblong +  and ellipsoid or oval +
James L. Reveal +
Greene +
deciduous +  and persistent +
stipelike +
Undefined subg. Eucycla +
papillate +
awn-tipped +  and simple +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
greenish +  and cinereous +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
glabrate +  and white-tomentose +
linear;narrowly oblong +
0.1cm;0.4cm +
not awn-tipped +
leaflike +  and semileaflike +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
glandular +, pubescent +  and glabrous +
lanceolate +  and oblong +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
not brittle +
spreading +  and erect +
scabrellous +
ridged +, angled +  and round +
spreading +  and erect +
whorled +, opposite +  and alternate +
Santa Cruz Island wild buckwheat +
10-600 m +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
unisexual +, , +  and bisexual +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 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 +
Rocky slopes and canyon walls, coastal scrub communities +
reduced +
capitate +  and subcapitate +
15 cm150 mm <br />0.15 m <br /> (20 cm200 mm <br />0.2 m <br />) +
dense +  and diffuse +
cymelike +, paniclelike +, racemelike +  and spikelike +
connate +  and free +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
campanulate +
nonmembranous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 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 +
erect to deflexed +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
cylindric +  and urceolate +
accrescent +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering Apr–Oct. +
homostylous +  and 3-carpellate +
Bull. Calif. Acad. Sci. +
, +  and solid +
slender;stout +
persistent +
decumbent to erect +  and prostrate +
spreading +  and erect +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
? (?) +  and ? (?) +
coriaceous +  and membranous +
consisting of a series +  and tubular +
distinct +
erect;spreading or recurved +
chambered +  and solid +
Slender (?) +  and Stout (?) +
Eriogonum arborescens +
Eriogonum subg. Eucycla +
species +
emarginate +  and entire +
0 +  and 1/2 +
oblanceolate +  and narrowly obovate +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
persistent +
membranous +
pubescent +  and glabrous +
reddish +  and cinereous +
plant +  and shrub +
synoecious +, monocarpic +, polycarpic +  and , +
3 +, 2 +  and 1 +