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| ## flatpea {#flatpea .Title-Header}                                   |
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| *Lathyrus sylvestris* L.                                              |
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| Plant Symbol = LASY                                                   |
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Contributed by: USDA NRCS Plant Materials Program

![Color image of Flatpea (Lathyrus
sylvestris)](media/image2.png){width="2.9929133858267716in"
height="2.0661417322834645in"}

**Uses**

Flatpea is a long-lived erosion control plant that can grow on severely
disturbed soil under acid conditions and begin a soil improvement
process. It requires little input once established. Flatpea will inhibit
the ability of other plants to invade the stand after it acheives full
cover, and can be used to control woody plant encroachment of utility
rights-of-way. Flatpea has also received extensive interest as a forage
due to the high protein content, however the presence of high
concentrations of diaminobutyric acid (DABA) has rendered this use
unlikely. DABA is toxic to non-ruminent livestock, and also to ruminants
if fed in quantity before the rumen is acclimated to it. Birds will
utilize the seed and are not affected by DABA.

##### 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 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}

Flatpea climbs through the use of tendrils and can attain heights of 5-7
feet if support is available. When no support is nearby, the plant has a
height of 18-30 inches. In either case, a well-established stand forms a
dense mat of vegetation. The stems and petioles are winged with
leaf-like appendages. The leaf consists of two long, narrow leaflets
with parallel veins and bears the tendril from juncture of the leaflets.
The flowers are deep pink, and produce 2-inch long seed pods that
contain the hard round seed. Both the seed and the pod are black or dark
gray at maturity. Flatpea closely resembles sweetpea and perennial pea.

##### Adaptation and Distribution {#adaptation-and-distribution .Header-3}

Flatpea is adapted throughout the Northeast to soils that are moderately
well drained or drier. It may also grow well on some sloping soils that
are somewhat poorly drained. It is drought tolerant once established,
and will grow on soils with a fines content as low as 15 percent
(passing a 200 mesh seive). Low fertility and acid soils can
successfully grow flatpea, and it will tolerate moderate shade better
than will crownvetch.

Flatpea is distributed primarily in the northwest and scattered
throughout the eastern United States. For a current distribution map,
please consult the Plant Profile page for this species on the PLANTS
Website.

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

Flatpea will not establish successfully unless the seed is incorporated
into the soil. Broadcast and hydroseeding will not work unless
subsequent erosion covers the seed, or a heavy mulch is applied. The
best way to incorporate flatpea seed on disturbed sites is to track it
in with a bulldozer. Inoculated flatpea seed must be spring planted, or
dormant planted in mid-fall. A drill can also used to plant the seed 1-1
1/2 inches deep. Flatpea is always planted with a grass companion
(typically tall fescue) to provide quick cover during the 2-3 year
establishment period. With good agronomics on a good site, flatpea will
cover the soil in 2 years. With poor methodology it may never be
successful.

Lime is needed if the soil is below a pH of 5.0, and moderate levels of
phosphorus and potash are beneficial. Coat the seed with the specific
inoculant immediately prior to planting. Plant flatpea at 20 pounds per
acre with 15 pounds of tall fescue. More seed will not make up for lack
of incorporation as outlined above.

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

None is required. Mow the stand no more than once per year, after full
bloom, and no sooner than the third year after planting.

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

**'**Lathco' (western WA) is the only cultivar, and is available in the
seed trade.

##### Control {#control .Header-3}

Please contact your local agricultural extension specialist or county
weed specialist to learn what works best in your area and how to use it
safely. Always read label and safety instructions for each control
method. Trade names and control measures appear in this document only to
provide specific information. USDA, NRCS does not guarantee or warranty
the products and control methods named, and other products may be
equally effective.

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

USDA NRCS Plant Materials Program

##### 

##### Edited: 05Feb2002 JLK; 060802 jsp {#edited-05feb2002-jlk-060802-jsp .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/)\>

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*To file a complaint of discrimination write USDA, Director, Office of
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