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| ## burclover {#burclover .Title-Header}                               |
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| *Medicago polymorpha* L.                                              |
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| Plant Symbol = MEPO3                                                  |
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Contributed by: USDA NRCS Plant Materials Program

![](media/image2.jpeg){width="3.0569444444444445in"
height="2.0368055555555555in"} © Larry Allain

[USGS NWRC](http://www.nwrc.usgs.gov/)

**Caution: This plant may become invasive.**

##### Uses {#uses .Header-3}

*Livestock*: All classes of livestock except horses and mules will eat
burclover readily, especially when the plant is maturing. Mature stands
are highly nutritious and, when abundant, may serve as a finishing feed
for lambs. Where growth is lush, the herbage has been known to cause
bloat in livestock, particularly those unaccustomed to grazing it. Heavy
use of the pods is most noticeable after the spiny burs have been
softened by fall rains. While summer grazing burclover, sheep often
accumulate numerous burs in the wool, lessening the value of the clip.

*Cropland*: Burclover is commonly used as a cover crop in orchards. Its
rapid, dense growth characteristics and its ability as a legume to fix
nitrogen and thus increase the available soil nitrogen supply add to its
value for such use. Burclover is particularly useful in orchards and
vineyards as a reseeding annual used in association with strip cover
management. It can be mowed to control excessive growth, which will not
hinder its ability to produce a seed crop for the next year. After seed
maturity it can be mowed or disked.

*Wildlife*: Quail and deer make extensive use of the dry burs.

##### Status {#status .Header-3}

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status (e.g. threatened or endangered
species, state noxious status, and wetland indicator values).

##### Weediness {#weediness .Header-3}

This plant is considered noxious in Arizona. This plant may become weedy
or invasive in some regions or habitats and may displace desirable
vegetation if not properly managed. Please consult with your local NRCS
Field Office, Cooperative Extension Service office, or state natural
resource or agriculture department regarding its status and use. Weed
information is also available from the PLANTS Web site at
plants.usda.gov.

##### Description {#description .Header-3}

*Medicago polymorpha* L., burclover, is a shallow-rooted annual legume.
The characteristic growth habit of burclover is one of numerous
prostrate stems branching from the crown and spreading outward 6 to 30
inches. Where thick stands develop stems may become erect, obtaining
heights of 18 to 24 inches in more favorable years. The leaves are
subglabrous and clover-like in appearance, with leaflets normally
wedge-shaped and toothed toward the top. The inflorescence is usually
quite limited, presenting only a few small, yellow, pea-like flowers.
The several-seeded fruit is a flattened, coiled pod, commonly up to 1/4
inch in width and fringed with a double row of conspicuous, hooked
spines. Well developed plants may produce more than 1,000 pods. The seed
is rather large for a legume of this type, usually developing to over
3/32 inch in length.

Although often considered an indigenous California plant, burclover was
introduced from southern Europe. Burclover has become extensively
naturalized in the United States from cultivation as a hay or cover
crop. It is one of the more widely recognized *Medicago* species,
especially west of the Sierra Nevada and Cascade Mountains, where it is
most abundant.

##### Adaptation {#adaptation .Header-3}

Burclover may occur in pure stands, but most often it is associated with
other winter annuals, such as soft chess, wild oats, and filaree
species. As a winter annual, burclover germinates in autumn following
the first rains of the season and matures early in the summer. It is
particularly adapted to mild, moist winters and hot, dry summers.
Optimal annual rainfall for burclover is 10 to 25 inches.

Although burclover will succeed in many soil types, heavy loams are most
suitable and valleys and low foothills are generally the preferred sites
of natural plant development. This species inhabits all exposures and
grows well under light conditions varying from full sunlight to heavy
shade. It is tolerant of slightly alkaline conditions and is less acid
tolerant than subterranean clover. Favorable growth is usually
restricted to a soil pH range of 4.7 to 8.0. Flowering period for
burclover commonly begins in February. On very moist soils, the plants
are later maturing than on well-drained lands.

For a current distribution map, please consult the Plant Profile page
for this species on the PLANTS Website.

##### Establishment {#establishment .Header-3}

Burclover does poorly on soils of low fertility. In establishing stands,
except on very fertile soils, the use of fertilizer is routinely
recommended. Growth is especially poor on droughty, sulfur deficient,
granite soils and fertilization with sulfur and phosphorous is required.

Seedings of burclover are made in late summer or early fall. Later
seeding provides little time for fall and winter growth and plants are
more susceptible to cold temperatures and frost-heaving. The recommended
seeding rate is 9 pounds per acre. In dry areas, one irrigation period
just before seeding is ordinarily required. Earlier seeding or unusually
dry falls may necessitate a second irrigation to keep seedlings from
being lost to drought.

Naturalized stands of burclover usually have adequate seed inoculation.
For added success in developing new stands, inoculation of the seed with
commercial inoculate is recommended. Scarification of the seed may also
be necessary to ensure proper establishment.

##### Management {#management .Header-3}

Where burclover is adapted on rangeland, seeding is usually not
necessary as the seed is already present. Production can be enhanced
with cultivation, fertilization and proper grazing management. Existing
stands in orchards and vineyards will continue to re-seed indefinitely
under proper management. Wait for seed to mature before spring tillage.
Don\'t apply herbicide to strips intended for cover crop. Use
phosphorous and sulfur to encourage burclover in mixed grass-clover
stands.

##### Cultivars, Improved, and Selected Materials (and area of origin) {#cultivars-improved-and-selected-materials-and-area-of-origin .Header-3}

No cultivars are specifically recommended. Other species of burclover
include *Medicago rigidula* (L.) All. and *Medicago hispida* Gaertn.
Seeds are available at commercial seed stores in the west.

##### Prepared By & Species Coordinator:  {#prepared-by-species-coordinator .Header-3}

USDA NRCS Plant Materials Program

##### 

##### Edited: 05Feb2002 JLK; 25may06jsp {#edited-05feb2002-jlk-25may06jsp .Header-4}

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

*The U.S. Department of Agriculture (USDA) prohibits discrimination in
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origin, sex, religion, age, disability, political beliefs, sexual
orientation, and marital or family status. (Not all prohibited bases
apply to all programs.) Persons with disabilities who require
alternative means for communication of program information (Braille,
large print, audiotape, etc.) should contact USDA\'s [TARGET
Center](http://www.usda.gov/oo/target.htm) at 202-720-2600 (voice and
TDD).*

*To file a complaint of discrimination write USDA, Director, Office of
Civil Rights, Room 326-W, Whitten Building, 14th and Independence
Avenue, SW, Washington, DC 20250-9410 or call 202-720-5964 (voice or
TDD). USDA is an equal opportunity provider and employer.*

*Read about [Civil Rights at the Natural Resources Convervation
Service](http://www.nrcs.usda.gov/about/civilrights/).*