florida Early Detection Network


Summer cypress, Common kochia, Fireweed, Mexican fireweed, Mock cypress


Kochia scoparia (L.) Schrad.


Goosefoot family


Kochia scorparia



Synonyms: Bassia scoparia (L.) A.J. Scott, Bassia sieversiana (Pallas) W.A. Weber, Kochia alata Bates, Kochia sieversiana (Pallas) C.A. Mey., Kochia trichophila Stapf


Botanical Glossary

Kochia scoparia is a bushy annual that grows to about 1.5 m (5 ft.) in height. The plant is covered in soft hairs. The leaves are sessile, narrowly lanceolate and often pubescent. The apex of the leaf is acuminate. The leaves measure 2.5-5 cm (1-2 in.) in length and 2-4 mm (0.08-0.2 in.) in width. They gradually become smaller towards the top of the plant. Kochia scoparia flowers from July to September. The inconspicuous flowers are sessile and located in the upper bracts of the plant, forming spikes that measure 5-10 mm (0.2-0.4 in.) long. The spikes are covered in long, soft hairs. The star-shaped calyx is 2.5 mm (0.1 in.) wide when mature. The calyx segments, when fruiting, each have a short triangular wing that covers the fruit. The dull brown seeds are small, measuring 1.5 mm (0.06 in.) wide. Page References Bailey 353, Fernald 591, Gleason & Cronquist 99, Holmgren 90, Magee & Ahles 451. See reference section below for full citations.


Bassia hyssopifolia (Pallas) Kuntz (smotherweed), Bassia hirsuta (L.) Aschers. (hairy smotherweed) The leaves of Bassia hyssopifolia are more blunt and shorter than those of Kochia scoparia. The stems of B. hyssopifolia are whitish, while those of K. scoparia tend to be reddish in color. Bassia hirsuta is typically much shorter than Kochia scoparia and has a more arcuate, less upright, habit. Its leaves also tend to be wider and are shorter than those of K. scoparia.


Kochia scoparia reproduces by copious seed production. The seeds are dispersed mechanically; both wind and water constitute effective means of seed dispersal. The plants themselves can even roll in a manner similar to a tumbleweed. Once dispersed, its seeds are short-lived in the soil; however, they tend to germinate early, and the resulting seedlings have a high degree of vigor.


Kochia scoparia is native to Eurasia. It is presently found throughout the U.S., with the exception of the southeastern states and Arkansas. It is also common in Quebec and the prairie provinces of Canada. It is most invasive in the western United States, where it has become a serious agricultural weed. It has been reported in all of the states of New England.


The precise timing of Kochia scoparia's introduction to New England is unclear. It was most likely introduced as a garden plant, cultivated for its attractive fall foliage. Robinson (1908) described it as "locally established as a weed." Early records from Connecticut (1907 to 1912) place it in waste ground, roadsides, in a yard as a garden escapee, and on the edge of a salt marsh. Fernald (1950) describes it as having "spread from cultivation" from New England toward the West and South.


Abandoned Field, Agricultural Field, Coastal Grassland, Edge, Open Disturbed Area, Pasture, Salt Marsh, Vacant Lot, Yard or Garden. Kochia scoparia is mostly found along the coast, in disturbed sites, along roadsides, and in grassy fields. Since it is both drought and salt tolerant, it is found in sandy areas and along the edges of salt marshes. It can also be found along waterways and on floodplains (this is more common out West), particularly in more disturbed areas.


Kochia scoparia can be a rapid colonizer in high light situations, and has the ability to suppress native species in such habitats. It has some degree of allelopathy. It can be toxic to cattle if grazed heavily.


Saskatchewan Agriculture, Food and Rural Revitalization


Documentation required: A specific photograph or mounted snippet of the inflorescence. Best time for documentation: Summer, fall.


Integrated Taxonomic Information System Taxonomic information

The PLANTS Database General information and a map

USDA Fire Effects Information System A wide variety of information including a description, ecology and other aspects of the species

University of California Statewide Integrated Pest Management Project A brief description and images

Saskatchewan Agriculture, Food and Rural Revitalization Brief description and control methods


Andersen, R.N. 1968. Germination and Establishment of Weeds for Experimental Purposes. Weed Science Society of America Handbook. WSSA, Illinois.

Bailey, L.H. 1949. Manual of Cultivated Plants. Macmillan, New York.

Fernald, M.L. 1950. Gray's Manual of Botany 8th ed. Dioscorides Press, Portland OR.

Gleason, H.A. 1952. The New Britton and Brown Illustrated Flora of the Northeastern United States and Adjacent Canada. Macmillan Publishing Co., Inc. New York.

Gleason H.A. and A.C. Cronquist. 1991. Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden, Bronx, New York.

Holmgren N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. New York Botanical Garden, Bronx, New York.

Magee D.W and H.E. Ahles. 1999. Flora of the Northeast. University of Massachusetts Press, Amherst.

Robinson, B.J. 1908. Gray's New Manual of Botany 7th ed. American Book Co., New York, NY.

Stubbendieck, J., G.Y. Friisoe, M.R. Bolick. 1994. Weeds of Nebraska and the Great Plains. Nebraska Department of Agriculture, Bureau of Plant Industry. Lincoln, Nebraska. 589 pp.

USDA, NRCS. 2001. The PLANTS Database, Version 3.1. (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.