Erigeron arisolius

G. L. Nesom

Phytologia 69: 243. 1990.

Common names: Dry-sun fleabane
Treatment appears in FNA Volume 20. Treatment on page 337. Mentioned on page 264.

Annuals or short-lived perennials, 30–70 cm; taprooted. Stems erect, coarsely hirsute to hispid (hairs only along ribs, bases thickened), minutely glandular. Leaves mostly cauline; blades linear to linear-oblong, lanceolate, or oblanceolate (slightly narrowed distally), 25–50 × 2–5 mm, margins entire or sometimes lobed (lobes 1–2 pairs, coarse, rounded), faces hispido-strigose. Heads 20–50+ in loose, corymbiform arrays (buds erect). Involucres 2.5–3.5 × 5–8 mm. Phyllaries in 3–4 series, minutely hispid, minutely glandular. Ray-florets 125–180; corollas usually white, sometimes lavender or pinkish, 6–7 mm, laminae reflexing. Disc corollas 2–2.5 mm (throats indurate and inflated). Cypselae 0.7–1 mm, 2-nerved (nerves orange), faces sparsely strigose to glabrate; pappi: outer of setae or lanceolate scales, inner of (10–) 12–17 bristles. 2n = 18.


Phenology: Flowering May–Jun(–Nov).
Habitat: Grasslands, often in moist areas, sometimes with mesquite, openings, roadsides, oak, juniper, mesquite
Elevation: (800–)1300–1700 m

Discussion

Of conservation concern.

Erigeron arisolius is similar in general appearance to E. divergens; the erect buds and reflexing rays of E. arisolius contrast with the nodding buds and non-reflexing rays of E. divergens. Additionally, the latter has evenly distributed stem pubescence, cypselae with whitish nerves (versus orange), and fewer pappus bristles. Erigeron sceptrifer also may be difficult to distinguish from these: it is more similar to E. arisolius in vestiture and has shorter rays that usually become purple upon drying and that are downward-curved, compared to those of E. arisolius, where the rays dry a lighter color and reflex at the tube-lamina junction.

Selected References

None.

Lower Taxa

None.
... more about "Erigeron arisolius"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
Guy L. Nesom +
G. L. Nesom +
decurrent +
2.5 cm25 mm <br />0.025 m <br /> (5 cm50 mm <br />0.05 m <br />) +
linear;linear-oblong lanceolate or oblanceolate +
2mm;5mm +
rugulose +  and muricate +
Dry-sun fleabane +
not 2-lipped +  and actinomorphic +
pinkish +, lavender +  and white +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
subterete +, oblong +  and oblong-obovoid compressed +
fertile +  and bisexual +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
fertile +  and bisexual +
Ariz. +  and Mexico (Sonora) +
(800–)1300–1700 m +
sparsely strigose +  and glabrate +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Grasslands, often in moist areas, sometimes with mesquite, openings, roadsides, oak, juniper, mesquite +
disciform +  and discoid +
in loose , corymbiform or paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
turbinate;hemispheric +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
petiolate +  and sessile +
erect;spreading +
deltate +
Not (?) +  and Scarious (?) +
2-carpellate +
Flowering May–Jun(–Nov). +
3-nerved +  and 1-nerved +
narrowly elliptic +  and linear-lanceolate +
bearing subulate enations +, hairy +  and bristly +
lanceolate +
exalbuminous +
branched +  and simple +
prostrate +  and decumbent +
appendaged +  and truncate +
papillate +  and smooth +
Achaetogeron +  and Trimorpha +
Erigeron arisolius +
Erigeron +
species +
inflated +  and tubular +
90 cm900 mm <br />0.9 m <br /> (100 cm1,000 mm <br />1 m <br />) +
perennial +, short-lived +  and annual +
30 cm300 mm <br />0.3 m <br /> (70 cm700 mm <br />0.7 m <br />) +
tree +, shrub +  and subshrub +