Microseris howellii
Microseris douglasii
Howell's microseris, Howell's silverpuffs
Douglas' microseris, Douglas' silverpuffs
branched proximally and often distally.
basal and cauline; petiolate (petioles broadly winged, clasping);
blades linear to narrowly oblanceolate, 10–30 cm, margins entire, dentate, or pinnately lobed (lobes narrow, often retrorse).
basal; petiolate;
blades linear to oblanceolate, 3–25 cm, margins entire, dentate, or pinnately lobed (lobes slender, tapering), apices acute to acuminate, faces ± scurfy-puberulent.
erect (10–50 cm), ebracteate or leafy.
erect or curved-ascending, ebracteate.
narrowly ovoid in fruit, 8–17 mm.
globose to fusiform in fruit, 7–16 mm.
8–30;
corollas yellow, surpassing phyllaries by 5+ mm.
5–200;
corollas yellow or white, equaling or surpassing phyllaries by 1–3 mm.
sometimes purple-spotted, apices erect, acuminate, abaxial faces glabrous or scurfy-puberulent, often black-villous;
outer lanceolate to deltate;
inner lanceolate.
apices erect, acute to acuminate;
outer deltate, glabrous or lightly scurfy-puberulent;
inner lanceolate, faces often lightly black-villous on margins (midveins often purple-lined, thickened).
columnar, 4–7 mm;
pappi of 5–10, white, lanceolate, glabrous, aristate scales 3–6 mm, aristae barbellulate.
columnar or obconic, 3–10 mm;
pappi of (0–)1–5, white to yellow, brown, or blackish, aristate scales 0.5–7 mm (± arcuate, usually distinctly involute, except subsp. tenella, often abaxially villous, midveins usually tapering distally from thick bases, except subsp. tenella, widths less than 1/5 bodies), aristae (white or straw-colored, ± stout) barbellate.
= 18.
= 18.
Microseris howellii
Microseris douglasii
Of conservation concern.
Microseris howellii is known only from exposures of peridotite in Josephine County, Oregon. Although related to M. laciniata, it is ecologically isolated from the co-occurring members of that complex. Because of its limited range, it is listed as a threatened taxon by the Oregon Natural Heritage Program (2004).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Subspecies 3 (3 in the flora).
The geographic patterns of morphologic variability as well as both chloroplast and nuclear DNA markers in Microseris douglasii have been studied by K. Bachmann and J. Battjes (1994) and D. Roelofs and K. Bachmann (1997). Four chloroplast types were identified, two of which were derived by introgression from M. bigelovii or its ancestor. Plants in nature are highly inbred and genetically homozygous, as proposed earlier by K. L. Chambers (1955). Subspecies platycarpha stands well apart in these studies; subsp. tenella is not differentiated molecularly from subsp. douglasii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Pappus scales usually 0.5–1 mm, sometimes nearly obsolete; cypselae truncate-fusiform, ribs constricted at apices; s, w-c California, mainly coastal and Coast Ranges | subsp. tenella |
1. Pappus scales 1–7 mm; cypselae columnar or obconic, ribs slightly flared at apices | → 2 |
2. Pappus scales (glabrous) 0.5 mm shorter to 2 mm longer than cypselae; cypselae obconic or columnar, 3–4.5 mm; sw California, n Baja California | subsp. platycarpha |
2. Pappus scales (glabrous or villous) usually 1–6 mm shorter than cypselae; cypselae columnar (slightly tapered distally), 4–10 mm; widespread in cismontane California, mainly n of the Transverse Ranges | subsp. douglasii |
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
