Santa Monica Mountains Trails Council Plants Resource Page

Plant of the Month - Annual Coreopsis

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Plant Description

Common Name(s):Annual Coreopsis
Scientific Name:Leptosyne bigelovii
Plant Type:Annual
Size:up to 12 inches
Habitat:Oak Woodland
Blooms:February to June

Annual Coreopsis, Tickseed (Leptosyne californica) is an annual herb that is endemic to California. This plant is categorized as an Asteraceae (Sunflower in laymen terms). California Coreopsis grows at elevations of 30 to 600 meters (100 to 2,000 ft). The plant inhabits the following communities: Southern Oak Woodland, Valley Grassland, Joshua Tree Woodland, Creosote Bush Scrub. I have found this somewhat uncommon plant on the Ray Miller Trail and along the Triunfo Creek Trail.

The flowers of the Coreopsis plant are typical of many other Sunflower/Asteraceae species - comprising disk and ray flowers, but the slender and long green leaves set them apart; short. Leaves are considered basal (growing primarily around the base of the plant. There will be numerous green to reddish leafless stems, each topped by a single flower approximately one inch in diameter. Surrounding the disk flowers is a circle of yellow pigment that is subtle and oh so perfect. This daisy like flower is a composite type flower that comprises five to twelve ray florets (they appear to look like petals but are are in fact parts of a complete flower) and twenty to sixty disc florets. Each floret or disk flower is also a complete flower. Often you can see the disk flowers in different stages of maturity. Seeds are produced by the disk flowers. The Ray flowers are broad and notched at the tip, have a few lengthwise grooves and are generally sterile. Below the flower are two rows of flower parts known as Bracts (phyllaries); the upper (numbering eight) are pointed and yellow in color, while the lower (also numbering eight but joined at the base) are green. This makes it easier to identify this plant as a Coreopsis. Look at the images included with this page and you will see what I mean. Stems and leaves are smooth and hairless. The involucre of this plant reminds me of a Bell Pepper - what do you think?

Tickseed and Coreopsis refer to the seed of the flower. The relatively flat seeds are small, dry and look like bugs.

Leptosy'ne: from Greek leptos, "slender, thin, small, weak," and possibly syne, "together, joined"
bigelo'vii: John Milton Bigelow an Ohio Physician - Botanist is the source of this info.
Other Similar Plants:
California Aster Corethrogyne filaginifolia
Giant Coreopsis Coreopsis gigantea
Coyote Brush Baccharis pilularis
Bush Sunflower Encelia californica
California Thistle Cirsium occidentale var. californ
Mule Fat Baccharis salicifolia
Canyon Sunflower Venegasia carpesioides
Golden Yarrow Eriophyllum confertiflorum
Mugwort Artemisia douglasiana
Slender Sunflower Helianthus gracilentus
Common Sunflower Helianthus annus
San Diego Milk-aster Stephanomeria diegensis
Perezia, Sacapellote Acourtia microcephala
Cliff Aster Malacothrix saxatilis
Tejon Milk-Aster Stephanomeria cichoriacea
Rock Daisy Perityle emoryi
California Goldfields Lasthenia californica
Royal or Southern Goldfields Lasthenia coronaria
Lyons Pentachaeta Pentachaeta lyonii
Slender Tarweed Deinandra fasciculata
Common Yarrow Achillea millefolium
Sagebrush Artemisia californica

Originally featured: July 2017
Last modified: November 21 2018 17:33:53.
Wildflowers of the Santa Monica Mountains, by Milt McAuley
Flowering Plants: The Santa Monica Mountains, Coastal and Chaparral Regions of Southern California, by Nancy Dale
Images Botanical Terms for Leaves