Part I How lesser celandine grows
Part II Herbicide considerations
Part III Notes, including locations
and spray history

Lesser Celandine

Photographs and Notes

Photos taken in Sligo Creek Park except as noted

Part I How Lesser Celandine Grows

How to recognize lesser celandine

Lesser celandine has eight petals, and resembles a short-stemmed buttercup growing from a dense mat of leaves. It is an early bloomer, starting in mid-March. By June the leaves have disappeared for the year. Celandine belongs to the buttercup family (Ranunculaceae).

Lesser celandine has been introduced to gardens in the United States several times. The plant is found across Europe and Asia. It thrives in wetlands, and is uncommon on higher, drier sites.

Winter Aconite is an even earlier bloomer in the buttercup family. It has escaped to Sligo, but has not become a serious invasive plant.

Lesser celandine April 11, 2006 Winter Aconite March 8, 2004

How lesser celandine affects surroundings

Dense mats of lesser celandine cover acres in Little Falls near the Capitol Crescent Trail. In woods of Northwest Branch woods close to the Wheaton Horse Barn, smaller mats threaten Virginia bluebells.

At least three fields in Sligo were heavily matted in 2004. One was (and still is) the overgrown baseball field directly above Colesville Road. Native violets, spring beauty, mayapple and trout lily cannot compete. Less common wetland plants such as skunk cabbage and wild ginger (present in the Montgomery County part of Sligo only between Maple Avenue and Pine Branch) seem vulnerable too.

Little Falls April 14, 2006

A situation we are trying to avoid in Sligo. April 14, 2006

Old baseball field May 3, 2007

Violets, with deeply-veined leaves, in competition with celandine April 11, 2006

A remnant of spring beauty April 11, 2006

Even chickweed, a sturdy round-leaved plant from Europe, has trouble competing with celandine.
The paper square marked the site. April 12, 2007

Two weeks later, the same chickweed produced outreaching stems. April 29, 2007

In another week fewer runners showed, and chickweed seemed to be losing out. May 3, 2007

Growth of clumps

Clumps consist of separate plants, young and old. The oldest celandine plants, presumably in the middle of an area of several square yards, are no more crowded than plants at the periphery; apparently the older plants die, leaving room for new ones. These seem to be spread mainly, perhaps entirely, by vegetative means, not seed.

New celandine plants with several inches space between them probably start from seed.

A clump of about 25 square inches can contain more than a hundred individual plants. Feb. 21, 2008

Overview of an established area. Circle shows clump in next photo. Feb. 23, 2008

Clump from established area, showing spaces. Feb. 23, 2008

New growth in a clump that is probably two years old May 4, 2007.

Squares show one-year celandine plants which, judging by distance, must have started from seed.
(Sand was deposited on grass at the soccer field.) May 4, 2007

A similar situation in the woods. April 30, 2007

Buds, Flowers, and Seeds

By February the older plants, those with at least five leaves, produce globular buds that will flower in mid-March.

Globular bud in an older plant, which is growing many leaves at about the same time. Feb. 23, 2008

Buds transitioning to flowers March 31, 2007

Flower March 13, 2006

The flowers have flattened yellow stamens and a pistil made of green sections
which will become seeds (achenes). April 12, 2007

When petals fall, the pistil sections that will become seeds enlarge and darken at the tip. Many embryonic seeds are reported to naturally abort, but this has not kept celandine in Sligo from easily spreading.

Left, soon after petals have dropped. Right, about a week later.
(The string is attached to a tag for identification.) April 12, 2007

A slightly older seed. April 12, 2007

Older seeds. May 5, 2007

Browning seeds on a sprayed plant.
The left side shows several bulbils, which will produce new plants. May 4, 2007

A common relative of celandine, the kidney leaf buttercup, Ranunculus abortivus, is native
and is open at the same time. The pistil looks similar. May 5, 2007

Bulbils, tubers, and roots

Under the ground celandine has a number of tubers, with usually one that is especially long. Above the tubers are white roots. In May before plants close down for the year, stems lengthen, and buds of new tubers, called bulbils, sprout from the leaf stems. Soon afterward stems lengthen and drop, bringing bulbils into contact with the ground if they were not already. In spring each bulbil sprouts roots and a leaf. Judging from the appearance of plants in February, young plants will produce three to four leaves this year, but no flowers.

Tubers and white roots Feb. 21, 2008

Lengthened stems with bulbils May 4, 2007

Appearance of clumps when stems lengthen May 5, 2007

One-leaf plants becoming two-leaf. The bulbil appears to become the lead tuber. Feb. 21, 2008

Three and four-leaf plants. The four-leaf plants are forming sheaths. Feb. 21, 2008

A four-leaf plant Feb. 21, 2008

Infrequently a plant produces two long tubers instead of one. Feb. 23, 2008

In mid-season the old lead tubers, now somewhat darker and smaller, shrivel. April 23, 2007

Roots and stems can pierce objects

One root grew through what seems to be a dead leaf and another pierced the harder twig-like material.
Note this is a young plant. Feb. 23, 2008

Through a microscope the twig-like material looks like an insect pupa.
Perhaps the three coils are root material.

Another root penetrating unidentified twig-like material. Feb. 21, 2008

Leaf stem penetrating a dead leaf. Feb. 23, 2008

Submitted by Sally Gagné
February 2008

Part II Herbicide considerations
Part III Notes, including locations
and spray history