Caley Pea

Scientific Name: Lathyrus hirsutus L.

Classification: Plantae/ Tracheobionta / Spermatophyta / Magnoliophyta / Magnoliopsida / Rosidae / Fabales / Fabaceae / Leguminosae / Lathyrus L./ Lathyrus hirsutus L.

Caley Pea
General Information
Usda SymbolLAHI2
GroupDicot
Life CycleAnnual
Growth HabitsForb/herbVine,
Native LocationsLAHI2

Plant Guide

Description

General: The name caley pea is credited to A.F. Caley, an Alabama farmer, who showed special interest in the plant (Baker, 1946). Caley pea is an introduced cool season annual legume in the Fabaceae/Leguminosae or pea family. The plant grows 1 to 3 feet tall (0.35 to 0.91 meters) and is a sprawling, climbing vine with glabrous flattened stems that branch occasionally (Fig. 1). Alternate compound leaves consist of a leaflet pair and climbing tendril. Leaflets are up to 3.5 inches long by 1 inch across (8.9 cm by 2.5 cm) and are ovate to oblong-ovate, glabrous with entire margins. Caley pea blooms in spring or summer depending on location. Flowers are up to 0.5 inch (1.3 cm) across and consist of two lateral petals and a keel. The petals vary in color from purple, pink, or white. Seedpods are flat sided, oblong, and covered with hairs. They progress from green to brown when mature. Mature seedpods split open to release circular, flattened, brown seeds about 0.08-inch-wide (2mm) (Fig.2) (Eason, 2018; Illinois Wildflowers 2020). Distribution: The Lathyrus genus contains 160 species from the north temperate zone, South America, and east Africa (Diggs, 1999). This genus is characterized by climbing growth habit and branched tendrils. Caley pea is native to the Mediterranean region and is naturalized in the United States (Diggs, 1999). It is found in the eastern half of Texas, lower Midwest, and southeastern U.S. (Eason, 2018; USDA NRCS Jimmy Carter Plant Materials Center, 2019). For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Habitat: Caley pea was originally grown in the U.S. as a forage or cover crop but escaped cultivation and is also found in thickets, savannas, roadsides, railroad right of ways, and field edges (Texas A&M University, 2020a; Illinois Wildflowers, 2020).

Adaptation

Caley pea prefers sites with partial to full sun. It is adapted to mildly acidic, heavy clay soils and calcareous clays with pH of 5.8 or higher. Caley pea is adapted to areas with 35 inches or greater annual precipitation and tolerates soils too wet for annual clovers (USDA, NRCS, 2020; USDA NRCS Jimmy Carter PMC, 2019).

Uses

Caley pea is grown for green manure crop, cover crop, organic nitrogen source, and livestock forage (Baker, 1946; USDA NRCS Jimmy Carter Plant Materials Center, 2019). Padgett et al. (2012) noted that Caley pea produced 2,704 to 7,666 lb/ac ( 3,028 kg/ha to 8,588 kg/ha) biomass as a cool season cover with an average yield of 3,968 lb/acre (4,447 kg/ha) and 135 lb. Natural Resources Conservation Service Plant Guide Figure 1. Caley pea foliage and bloom. Photo credit: Dr. Robin R. Buckallew, hosted by the USDA-NRCS PLANTS Database. Figure 2. Caley pea seeds. Photo credit: Steve Hurst, hosted by the USDA-NRCS PLANTS Database. 2 N/acre (151kg/ha) in Louisiana. Caley pea is utilized by wildlife. The foliage is browsed by whitetail deer and a food source for blister beetle (Epicauta fabricii) and caterpillars of the Oithona tiger moth (Grammia oithona). Bumblebees and long tongued bees pollinate the flowers (Illinois Wildflowers, 2020). Quail and other birds consume the seeds (Noble Research Institute, 2020).

Status

Threatened or Endangered: Caley pea is not threatened or endangered (US Fish and Wildlife Service, 2020) Wetland Indicator: Caley pea is a facultative (FAC) plant in the Atlantic and Gulf Coastal Plain, Arid west, Eastern mountains and Piedmont, Great Plains, and Western mountains, Valleys, and Coast regions and a facultative upland (FACU) plant in the Midwest and Northcentral and Northeast regions of the U.S. Facultative plants occur in wetlands and non-wetlands while facultative upland plants usually occur in non-wetlands (US Army Corps of Engineers, 2020). Weedy or Invasive: 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, state natural resource, or state agriculture department regarding its status and use. Please consult the PLANTS Web site (http://plants.usda.gov/) and your state’s Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland indicator values).

Planting Guidelines

Recommended seeding date is Sept. 15 to Nov. 30 and seeding rate 35 PLS lb/acre in east Texas (USDA NRCS, 2018). There are approximately 18,000 seeds/lb (Mason et al., 2019). Consult your local USDA NRCS Field Office for recommended planting dates and rates in your area. Take soil samples to determine soil pH and fertility level before planting. Amend soil pH to at least 5.8 and apply nutrients according to soil test recommendations (USDA NRCS Jimmy Carter Plant Materials Center, 2019). Scarify and inoculate seed with appropriate pea/vetch rhizobium before planting. Prepare the site by mowing and applying a broad-spectrum herbicide for no till planting. Plant seed ½ to 1 inch deep using a no-till drill equipped with depth bands to control seed placement. For conventional planting, prepare a weed free seedbed using light tillage and a cultipacker to smooth and firm the seedbed prior to planting. Allow rain or irrigate to germinate weed seed and then apply a broad-spectrum herbicide to eliminate weed seedlings. Plant seed with a conventional seed drill after herbicide application. For broadcast seeding, prepare a conventional seedbed and control weeds. Broadcast the seed directly on the site and cover the seed to create a good seed-to-soil contact. Increase seeding rates 10-25% for broadcast seeding.

Management

Cool season legume cover crops provide biomass to protect the soil in winter and early spring and nitrogen for a subsequent crop. Terminate Caley pea cover crops in late spring to maximize these benefits. Allow cover crop residue to dry out or desiccate for at least two weeks before planting the spring crop to reduce number of surviving insects and diseases (Padgett et al., 2012). Caley pea vegetation is nutritious but toxic amino acids and nitriles are concentrated in their seeds (Texas A&M University, 2020a). Domestic livestock consuming maturing plants and seedpods with these amino acids and nitriles may experience a toxic reaction known as Lathyrism poisoning (Holbrook et al., 2015). Horses are affected by the amino acid β-ODAP (3 β-N-oxalyl-L-α, β-diaminopropionic) in Caley pea and should not graze it or eat hay contaminated with dried plants or seedpods (HorseDVM, 2020; Holbrook et al., 2015). Cattle are typically poisoned when they graze pastures with an abundance of mature plants (Texas A&M University, 2020a). Chickens and pigs are also sensitive to the toxin (Baker, 1946). Poisoning symptoms include incoordination or paralysis of rear legs, exaggerated stepping, and reluctance to rise or stand (Texas A&M University, 2020a). Monitor livestock pastures for caley pea abundance and plant maturity. Remove livestock before Caley pea begins blooming or if the threat of poisoning is a concern. Consult your local livestock extension specialist for assistance with grazing Caley pea.

Pests and Potential Problems

Pests include root knot nematode (Meloidogyne sp.) and dodder (Cuscuta sp.). Root knot nematodes create root galls and dodder is a parasitic plant which wraps around and inserts adventitious roots into a host plant. The adventitious roots extract water, minerals, and nutrients from the host (Missouri Botanical Garden, 2020). Seedlings are subject to damping off caused by Rhizoctonia solani, Pythium sp., or Fusarium sp. soil fungi. Anthracnose (Colletotrichum pisi), scab, (Cladosporium herbarum), and powdery mildew, (Erysiphe polygoni) are other diseases affecting Caley pea (Texas A&M University, 2020).

Environmental Concerns

Concerns , Use soil moisture sensors to measure the soil moisture of Caley Pea.

Concerns

Caley pea has no known detrimental effects on the environment.

http://plants.usda.gov/ 3

Control

Control Caley pea by mechanical means such as mowing or applying a broad-spectrum herbicide. 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. 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.

Seed Production

Refer to Planting Guidelines for appropriate seeding rates, dates, and planting methods. Caley pea begins blooming in late April to May and develops seedpods in late May or June in the Western Gulf Region (Wolff, 1951). Seedpods do not ripen uniformly. Do not wait until all seedpods are mature before harvesting as they shatter during the warmest part of the day (Wolff, 1951). Harvest the seed crop with a combine when about 90% of the seedpods are brown. Use a low harvest height, a wide cylinder and concave spacing, and a cylinder speed below 1000 RPM. If not dried properly, seed will heat if stored in sacks or a bin. Instead, stir and air-dry harvested seed until danger of heating is over then partially clean the seed using a seed scalper. Use a seed cleaner with air adjustments and separation screens to remove chaff and unfilled seed. For 3 screen cleaners, recommended top screen size is 3/8 inch, the middle screen should have holes large enough for seeds to fall through, and the third or bottom screen holes smaller than the seeds to remove any small chaff. Screen sizes may differ each year depending on harvested seed size (Wolff, 1951). Cleaned seed yields averaged about 800 lb/acre (896 kg/ha) with fertile fields yielding 2000 lb/acre (2,241 kg/ha) in the Western Gulf Region (Wolff, 1951). Seed purity was 96% with 40% germination and 42% hard seed. Store cleaned seed in a temperature and humidity-controlled environment. Wolff (1951) noted cleaned seed was usually not stored more than two years before planting. Cultivars, Improved, and Selected Materials (and area of origin) ‘AU GroundCover’ Caley pea is a composite of five best performing accessions chosen from evaluations at the USDA Jimmy Carter Plant Materials Center in Americus, Georgia. This variety was released jointly by Auburn University, Alabama Agricultural Experiment Station, and USDA NRCS Jimmy Carter Plant Materials Center in 1994. ‘AU GroundCover’ is adapted primarily to Alabama and Georgia and used for cool season cover crops and cattle forage. In clipping trials, it produced as much dry matter yield as common hairy vetch (Vicia spp.) and contained about 20% crude protein at flowering (Mosjidis et al., 1996). Select cultivars based on the local climate, resistance to local pests, and intended use. Consult with your local land grant university, local extension or local USDA NRCS office for recommendations on adapted cultivars for use in your area.

Literature Cited

Baker, K. 1946. Caley pea production and uses in Alabama. Progress Report Series No. 17. Alabama Polytechnic Institute. Auburn, Alabama. Diggs, G., B. Lipscomb, and R. O’Kennon. 1999. Shinners and Mahlers illustrated flora of north central Texas. Center for Environmental Studies and Department of Biology. Austin College, Sherman, Texas and Botanical Research Institute of Texas (BRIT), Fort Worth, Texas. Eason, M. 2018. Wildflowers of Texas. Timber Press Field Guide. Timber Press, Portland, Oregon. Holbrook, T., L. Gilliam, F. Stein, S. Morgan, A. Avery, A. Confer, and R. Panciera. 2015. Lathyrus hirsutus (Caley pea) intoxication in a herd of horses. J. Veterinary Internal Medicine 29:294-298. HorseDVM. 2020. Caley pea Lathyrus hirsutus. Accessed online 8/13/20 at http://www.horsedvm.com/poisonous/caleypea/ Illinois Wildflowers. 2020. Singletary pea. Accessed online 7/21/20 at https://illinoiswildflowers.info Mason, K., L. Dillard, K. Mullenix, and D. Ball. 2019. Alabama planting guide for forage legumes. Bulletin ANR-0150. Alabama A&M and Auburn University Extension. Normal and Auburn, Alabama. Missouri Botanical Garden. 2020. Dodder. Missouri Botanical Garden. St. Louis, Missouri. Mosjidis, J., C. Owsley, M. Kirkland, and K. Rogers. 1996. Registration of ‘AU GroundCover’ Caley pea. Crop Sci. 36:207. Noble Research Institute. 2020. Plant Image Gallery. Caley Pea. Accessed online 08/04/2020 at https://nobleapps.noble.org/plantimagegallery/

http://www.horsedvm.com/poisonous/caleypea/
https://illinoiswildflowers.info/
https://nobleapps.noble.org/plantimagegallery/ 4 Padgett, G., B. Leonard, J. Kruse, D. Stephenson, D. Boquet, and R. Hutchinson. 2012. Louisiana conservation tillage handbook. Pub. 3216. LSU AgCenter and LSU College of Agriculture. Louisiana State University. Baton Rouge, Louisiana. Texas A&M University. 2020. Plant disease handbook. Accessed online 7/21/20 at https://plantdiseasehandbook.tamu.edu/industry-specialty/forage-crops/austrian-winter-peas-and-singletary-pea/ Texas A&M University. 2020a. Plants of Texas Rangelands. Virtual herbarium. Accessed online 7/25/20 at https://rangeplants.tamu.edu/plant/singletary-pea/ US Army Corps of Engineers. 2018. National wetland plant list. US Army Corps of Engineers. US Fish and Wildlife Service. 2020. ECOS-Environmental Conservation Online System. US Fish and Wildlife Service. USDA NRCS Jimmy Carter Plant Materials Center. 2019. Release brochure for ‘AU GroundCover’ Caley pea (Lathyrus hirsutus). USDA NRCS Jimmy Carter Plant Materials Center. Americus, Georgia. USDA NRCS. 2018. NRCS Electronic Field Office Technical Guide - Appendix 1-planting rates for seeding and sprigging in Texas, Zone 4. USDA NRCS Texas. Temple, Texas. USDA, NRCS. 2020. The PLANTS Database (http://plants.usda.gov, 5 August 2020). National Plant Data Team, Greensboro, NC 27401-4901 USA. Wolff, S. 1951. Harvesting and cleaning grass and legume seed in the western gulf region. Agricultural Handbook No. 24. USDA Soil Conservation Service. Fort Worth, Texas. Citation Brakie, M. 2020. Plant Guide for Caley pea (Lathyrus hirsutus). USDA-Natural Resources Conservation Service, East Texas Plant Materials Center. Nacogdoches, Texas 75964. Published Edited: For more information about this and other plants, please contact your local NRCS field office or Conservation District at http://www.nrcs.usda.gov/ and visit the PLANTS Web site at http://plants.usda.gov/ or the Plant Materials Program web site: http://plant-materials.nrcs.usda.gov. PLANTS is not responsible for the content or availability of other Web sites. In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA's TARGET Center at (202) 720-2600 (voice and TTY) or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available in languages other than English. To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at How to File a Program Discrimination Complaint and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: program.intake@usda.gov. USDA is an equal opportunity provider, employer, and lender.

Plant Traits

Growth Requirements

Temperature, Minimum (°F)17
Adapted to Coarse Textured SoilsYes
Adapted to Fine Textured SoilsYes
Adapted to Medium Textured SoilsYes
Anaerobic ToleranceNone
CaCO3 ToleranceLow
Cold Stratification RequiredYes
Drought ToleranceNone
Fertility RequirementMedium
Fire ToleranceNone
Frost Free Days, Minimum120
Hedge ToleranceNone
Moisture UseHigh
pH, Maximum6.2
pH, Minimum5.8
Precipitation, Maximum60
Precipitation, Minimum35
Root Depth, Minimum (inches)12
Salinity ToleranceNone
Shade ToleranceIntolerant


Morphology/Physiology

BloatLow
ToxicityNone
Resprout AbilityNo
Shape and OrientationClimbing
Active Growth PeriodFall, Winter and Spring
C:N RatioLow
Coppice PotentialNo
Fall ConspicuousNo
Fire ResistantNo
Flower ColorBlue
Flower ConspicuousYes
Foliage ColorYellow-Green
Foliage Porosity SummerModerate
Foliage Porosity WinterPorous
Fruit/Seed ColorBrown
Fruit/Seed ConspicuousYes
Growth FormMultiple Stem
Growth RateRapid
Height, Mature (feet)3.0
Known AllelopathNo
Leaf RetentionNo
Low Growing GrassNo
Nitrogen FixationHigh
Foliage TextureFine


Reproduction

Propagated by CuttingsNo
Propagated by SeedYes
Propagated by SodNo
Propagated by SprigsNo
Fruit/Seed PersistenceNo
Propagated by TubersNo
Seed per Pound18160
Seed Spread RateModerate
Seedling VigorHigh
Small GrainNo
Propagated by ContainerNo
Propagated by BulbNo
Propagated by Bare RootNo
Fruit/Seed Period EndSummer
Fruit/Seed Period BeginSpring
Fruit/Seed AbundanceLow
Commercial AvailabilityNo Known Source
Bloom PeriodSpring
Propagated by CormNo


Suitability/Use

Veneer ProductNo
Pulpwood ProductNo
Protein PotentialHigh
Post ProductNo
Palatable HumanNo
Palatable Graze AnimalHigh
Palatable Browse AnimalHigh
Nursery Stock ProductNo
Naval Store ProductNo
Lumber ProductNo
Fodder ProductYes
Christmas Tree ProductNo
Berry/Nut/Seed ProductNo

Caley Pea