Chrysanthemum leucanthemum L. - Daisy

Chrysanthemum leucanthemum plant

Family - Asteraceae

Stems - To +1m tall, herbaceous, multiple from base, from rhizomes and fibrous roots, simple or branched above, glabrous, angled.

Chrysanthemum leucanthemum stem

Leaves - Alternate, sessile above, petiolate below, clasping or not, irregular serrate to lobed near base, glabrous, to +10cm long, +2cm broad. Some leaves with lobes extending almost to midrib. Lower leaves spatulate.

Chrysanthemum leucanthemum leaf

Inflorescence - Single flower head terminating stem.

Involucre - To 2cm broad, 4-5mm tall. Phyllaries imbricate, glabrous, lanceolate, with scarious margins, green with brown near margins.

Chrysanthemum leucanthemum involucreInvolucre.

Ray flowers - Sterile. Ligules white, toothed at apex, to +2cm long, 5mm broad. Achenes glabrous. Pappus absent.

Chrysanthemum leucanthemum flowers

Disk flowers - Disk to +2cm broad. Corolla 5-lobed, yellow. Tube to 3mm long. Achenes brown, 10-nerved (ribbed), glabrous, 2.1mm long. Pappus absent. Receptacle convex.

Chrysanthemum leucanthemum diskDisk close-up.

Flowering - May - August.

Habitat - Fields, pastures, waste places, roadsides, railroads, prairies, slopes, disturbed sites.

Origin - Native to Europe.

Other info. - This extremely common plant can be seen growing along roadsides and in waste places throughout Missouri in the early summer. It is simple to identify as nothing else in our wild flora gets such a large white flower head.
According to Steyermark there are two varieties in Missouri. Variety leucanthemum has middle and upper cauline leaves with teeth at base that are larger than the other teeth on leaf. Also, the basal leaves are regularly toothed.
Variety pinnatifidum has middle and upper cauline leaves with conspicuous lobes extending nearly to midrib(pinnatifid). The basal leaves are also pinnatifid to irregularly toothed.
A synonym for the species is Leucanthemum vulgare Lam.

Photographs taken at off Hwy 106, Reynolds County, MO., 5-23-03, and off I-85 near Auburn, AL., 5-12-05.