Microseris acuminata

Greene

Bull. Torrey Bot. Club 10: 88. 1883.

Common names: Sierra foothills silverpuffs
Endemic
Treatment appears in FNA Volume 19. Treatment on page 345. Mentioned on page 339.

Annuals, 5–35 cm; taprooted. Stems 0. Leaves basal; petiolate; blades linear to narrowly elliptic, 3–20 cm, margins usually pinnately lobed (with narrow rachis and linear lobes), rarely entire, apices acuminate, faces glabrous or lightly scurfy-puberulent. Peduncles erect or curved-ascending, ebracteate. Involucres ovoid to fusiform in fruit, 10–22 mm. Phyllaries: apices erect, acute to acuminate, abaxial faces glabrous; outer deltate; inner lanceolate, (midveins often purple, thickened). Florets 5–50; corollas yellow, equaling or surpassing phyllaries by 1–3 mm. Cypselae columnar, 4.5–7 mm; pappi of 5, white or light-brown, linear-lanceolate, aristate scales 4–11 mm (arcuate, scarcely involute, apices acuminate, faces usually glabrous, rarely villous, midveins brownish, stout, widths 1/5–1/3 bodies, tapered distally), aristae (white or brown) barbellate. 2n = 36.


Phenology: Flowering Apr–Jun.
Habitat: Clay soils, flats and hillsides, sometimes near vernal pools, grasslands and open oak woodlands
Elevation: 30–600 m

Discussion

Microseris acuminata occurs in the Sacramento and northern San Joaquin valleys and surrounding foothills; it is disjunct in Jackson County, Oregon. K. L. Chambers (1955) proposed that this morphologically distinctive tetraploid species is of alloploid origin and that M. douglasii is one of its possible diploid parents. Recent molecular evidence (D. Roelofs et al. 1997) supports that relationship and also favors a relationship, through an extinct common ancestor, with the tetraploid M. campestris.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Microseris acuminata"
acute;acuminate +
scarious +
ovate +  and lanceolate +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
Kenton L. Chambers +
Greene +
decurrent +
compound +  and simple +
elliptic +  and linear to narrowly +
linear;lanceolate or oblanceolate +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
tuberculate +, rugose +, muricate +  and smooth +
filiform +
Sierra foothills silverpuffs +
zygomorphic +, actinomorphic +  and (3-)5-merous +
surpassing phyllaries +  and equaling +
purplish-spotted +, gray +  and brown or purplish +
Calif. +  and Oreg. +
30–600 m +
scurfy-puberulent +  and glabrous +
winged +  and beaked +
dispersed +
Clay soils, flats and hillsides, sometimes near vernal pools, grasslands and open oak woodlands +
indeterminate +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
ovoid;fusiform +
1 cm10 mm <br />0.01 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
2-carpellate +
light-brown +  and white +
persistent +
linear-lanceolate +
curved-ascending +  and erect +
Flowering Apr–Jun. +
connate +  and distinct +
5 +  and 40 +
Bull. Torrey Bot. Club +
flat;low-convex +
10 +  and 15 +
linear +, orbiculate +, ovate +, oblong +, lanceolate +  and deltate +
silvery;yellowish brownish or blackish +
5 +  and 30 +
aristate +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
exalbuminous +
many-branched +  and simple +
scurfy +  and glabrous +
few +, 1 +  and 30 +
appendaged +  and truncate +
papillate +
Apargidium +, Calaïs +  and Scorzonella +
Microseris acuminata +
Microseris +
species +
5 cm50 mm <br />0.05 m <br /> (35 cm350 mm <br />0.35 m <br />) +
shrub +  and subshrub +