Stebbinsoseris heterocarpa

(Nuttall) K. L. Chambers

Amer. J. Bot. 78: 1024. 1991

Common names: Grassland or derived silverpuffs
Basionyms: Uropappus heterocarpus Nuttall Trans. Amer. Philos. Soc., n. s. 7: 425. 1841
Synonyms: Microseris heterocarpa (Nuttall) K. L. Chambers
Treatment appears in FNA Volume 19. Treatment on page 347.
Peduncles 5–60 cm. Involucres 6–30 mm. Florets 10–125; corollas yellow or white. Cypselae gray, straw-colored, brown, or violet (dark purplish in southwest California), narrowly truncate-fusiform to columnar, 4.5–12 mm, each filled by embryo or distal 0.5–3 mm vacant and more slender than proximal part, apices slightly widened at bases of pappi; pappi 7–19 mm, scale bodies 4–11 mm, faces usually glabrous, rarely villous, aristae 3–8 mm. 2n = 36.

Phenology: Flowering Apr–Jun.
Habitat: Clay, gravelly, or rocky soils, open flats and hillsides, grasslands, oak woodlands, chaparral, coastal scrub, desert (rarely), roadsides
Elevation: 0–1000 m

Distribution

V19-542-distribution-map.gif

Ariz., Calif., Mexico (Baja California).

Discussion

Stebbinsoseris heterocarpa is widespread in cismontane California and disjunct to Gila and Yavapai counties, Arizona. Variation in enzymatic restriction sites in its chloroplast DNA and nuclear rDNA (R. S. Wallace and R. K. Jansen 1995) indicates that S. heterocarpa has arisen independently three or more times from hybrids of Microseris douglasii × Uropappus lindleyi. Reflecting this multiple origin, the species is more variable in pappi and cypsela size, color, and shape than S. decipiens, from which it is largely allopatric. Because M. douglasii subsp. tenella and M. bigelovii intergrade in some coastal areas, forms of S. heterocarpa having such hybrids as their maternal parent would be difficult to distinguish from S. decipiens (K. L. Chambers 1955; U. Lohwasser and F. R. Blattner 2004).

References

None.

Lower Taxa

No lower taxa listed.

AuthorKenton L. Chambers +
Authority(Nuttall) K. L. Chambers +
BasionymsUropappus heterocarpus +
Common nameGrassland or derived silverpuffs +
DistributionAriz. +, Calif. + and Mexico (Baja California). +
Elevation0–1000 m +
HabitatClay, gravelly, or rocky soils, open flats and hillsides, grasslands, oak woodlands, chaparral, coastal scrub, desert (rarely), roadsides +
IllustratorYevonn Wilson-Ramsey +
PhenologyFlowering Apr–Jun. +
Publication titleAmer. J. Bot. +
Publication year1991 +
ReferenceNone +
Source xmlhttps://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse grained fna xml/V19-20-21/V19 542.xml +
SynonymsMicroseris heterocarpa +
Taxon familyAsteraceae +
Taxon nameStebbinsoseris heterocarpa +
Taxon parentStebbinsoseris +
Taxon rankspecies +
VolumeVolume 19 +