Giant coreopsis is an erect, shrubby, glabrous few-branched perennial with a stout, fleshy trunk growing to some 8' tall.  The main trunk grows up to 5" thick and often resembles a small tree.  The leaves on a young plant are an array of pinnately-divided filiform segments, and on a mature plant are 3-4-pinnatifid into fleshy, linear segments clustered at the ends of branches.  The leaves are deciduous in the dry season when the plant is decidedly unattractive, but during its blooming season, March to May, it bursts forth with a mass of showy, bright yellow flowers and green leaves.  The large radiate flowering heads are in cymes on long scapiform peduncles and are up to 3" in diameter.  Each is leafy-bracted and has a bell-shaped involucre and two series of phyllaries, the outer of which are lance-oblong and the inner oblong-ovate.  There are 10-16 fertile yellow ray flowers and numerous yellow 4-toothed disk flowers.  The fruit is a glabrous, brown, obovate to oblong achene with no pappus.  Giant coreopsis may be found on rocky cliffs and exposed slopes and dunes along the immediate coast from Los Angeles Co. to San Luis Obispo Co. and on the Channel Islands.  A related species, C. maritima or sea dahlia, is smaller and grows further south.  These pictures were taken near Point Dume.

Click here for Latin name derivations: 1) Coreopsis 2) gigantea.
Pronunciation: kore-ee-OP-sis ji-GAN-tee-a.
Click here for Botanical Term Meanings.