Lessingia arachnoidea

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Campanulids
Ordo: Asterales

Familia: Asteraceae
Subfamilia: Asteroideae
Tribus: Astereae
Subtribus: Machaerantherinae
Genus: Lessingia
Species: Lessingia arachnoidea
Name

Lessingia arachnoidea Greene
References

Leaflets of Botanical Observation and Criticism. Washington, DC 2:29. 1910
USDA, ARS, Germplasm Resources Information Network. Lessingia arachnoidea in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 07-Oct-06.

Lessingia arachnoidea is a rare species of flowering plant in the daisy family known by the common name 'Crystal Springs lessingia'.[1] It is endemic to California, where it is known from a few occurrences in the vicinity of Crystal Springs Reservoir on the San Francisco Peninsula and southward to serpentine soil in Woodside. It may also exist in Sonoma County to the north.[2][3] The plant grows in chaparral, scrub, and other local plant communities, often on serpentine soils.

This is an annual herb producing a slender, erect stem up to 80 centimeters in maximum height. It is woolly toward the ends of the stems, less so toward the base of the plant. The leaves are narrow and sometimes toothed, the lowest approaching 11 centimeters long and the uppermost reduced in size. The inflorescence is made up of a single flower head at the tip of the slender stem. The flower head is lined with tiny lance-shaped phyllaries with purplish pointed tips and sometimes a coat of woolly fibers. The head is discoid, lacking ray florets but bearing several funnel-shaped lavender disc florets with raylike lobes. The fruit is an achene with a very hairy hard body 2 or 3 millimeters long and a small, bristly pappus on top.

Plants need bare soil or soil without any exotic weed competition to thrive, and can even grow in the bare soil of well worn trails. Late-flowering from August to October, and one of the last of the summer California wildflowers to bloom. Ripe seeds germinate readily, 40% in three days and 80% within 15 days. [4]
References

http://www.calflora.org/cgi-bin/species_query.cgi?where-taxon=Lessingia+arachnoidea
California Native Plant Society Rare Plant Profile
Flora of North America
Dremann, Craig Carlton. Field Notebook No.290, July-September 2020, pages 6, 23. Unpublished.