Name: Pisum sativum L.
Family: Fabaceae, the bean and pea family
Common Names: Pea, dry pea, Chinese pea, Chinese pea pod, Chinese snow pea, edible-podded pea, edible pod pea, podded pea, snow pea, sugar snap pea
Etymology: Pisum is an ancient Latin name for the well-known pea. Sativum means “planted,” or, more literally, “that which is sown” (6, 7).
Botanical synonyms (1, 6):
P. arvense L.
P. humile Boiss. & Noe
P. sativum L. ssp. arvense (L.) Poiret
P. sativum L. var. arvense (L.) Poir.
P. sativum L. var. humile Poir.
P. sativum L. var. macrocarpon Ser.
Quick Notable Features:
¬ Alternate, compound leaves
¬ Large stipules, often larger than leaflets
¬ Terminal leaflets modified as tendrils
¬ Rachis of compound leaf is often winged
Plant Height: pea plants grow regularly to 1-2 m (3). Plant height was one of the important variables coded by Mendel in his study of peas.
Subspecies/varieties recognized (2, 3):
P. sativum L. subsp. abyssinicum (A. Braun) Govorov
P. sativum L. subsp. elatius
P. sativum L. subsp. elatius pumilio
P. sativum L. var. hortense Asch. & Graebn.
P. sativum L. subsp. Sativum
These are only a few of the common subspecies and synonyms recognized; the University of Flora Vascular Plants Database has a complete listing. http://www.plantatlas.usf.edu/synonyms.asp?plantID=1795
Most Likely Confused with: Apios americana, species of Lathyrus, species of Vicia, Wisteria floribunda, and Wisteria sinensis.
Habitat Preference: The plant prefers well-drained sand, silt, or clay loam and is not shade tolerant. It prefers relatively cool and humid climates and escapees are usually found on shores or fields; it is rarely persistent once escaped (3, 5).
Geographic Distribution in Michigan: It has escaped in four isolated counties in Michigan, both in the lower and upper peninsulas: Oakland, Alpena, Houghton, and Baraga (5). The North American range includes the following states in the US: CA, CT, FL, IL, KS, KY,LA, <A, ME, MI, MO. MS. NC, NH, NY, OK, OR, PA, SC, UT, VA, WA and in Canada the following territories: MB, ON, and QC (1).
Known Elevational Distribution: No natural distribution was located in the literature, but peas are grown at high altitudes in the tropics and at sea level. The flora of Nepal lists the species from 1200 to 4000m (15) .Some reports indicate that high temperatures are more damaging than cool temperatures to pea plants.
Complete Geographic Distribution: This is an Old World species, native to Asia or possibly Europe and Southwest Asia (14). Now cultivated globally as one of the world’s most important vegetable crops (5).
Vegetative Plant Description: This glabrous, herbaceous vine has leaves that are alternate and pinnately compound. The leaflets are ovate, entire, 1.5 – 6 cm long and 1-4cm broad. There are 1–4 pairs of pinnately-veined leaflets per side with the terminal leaflet pair modified into a branched tendril. Leaflets are essentially sessile. The stipules are large, up to 10cm long (usually 1.5-8 cm), on round, slender, and glabrous stems. The midrib of the leaf rachis can be slightly winged (2,16).
Climbing Mechanism: This plant climbs using the tendrils produced at the apex of a compound leaf. These modified terminal leaflets form a branched tendril (pers. obs.).
Flower Description: Flowers are borne on axillary racemes of 1-3 flowers, each 1.5-3.5cm long. Calyx is campanualte (8-15mm) with teeth exceeding the tube in length. Corollas can be white, pink, or purple (2). Flowers have the classic “Faboid legume” form with 5 sepals, 5 zygomorphic petals (bilaterally symmetrical), 10 stamens in two groups (9 fused + 1 free) and a single superior carpel (pers. obs., SY). The standard petal is obovate, 1.6-3cm long and the glabrous ovary is nearly sessile. The style is flattened, curved, grooved longitudinally, and pubescent adaxially (14,16).
Pollinator: Self-pollination is possible in this species (2), but bees are also visitors (3).
Fruit Type and Description: The fruit is a legume. These are borne on a short pedicel, are 4-15 cm long and 1.5-2.5cm wide. The fruits are dehiscent both adaxially and abaxially, with each pod containing 2-10 seeds (2).
Seed Description: Seeds morphology varies greatly. They can be smooth or wrinkled, and globose or angled. Colors range from white to grey, green, or brown. Mature seeds are without the typical endosperm of most angiosperms and the cotyledons serve a nutritive role for the germinating seed (2,13).
Dispersal Syndrome: The pea is a widely distributed crop species but has rarely been encountered as an invasive and thus little is written about its dispersal. Pea fruits left on the vine may open along both sutures, dispersing seed by gravity but wild observations could not be found.
Distinguished by: Pisum sativum has terminal leaflets modified into tendrils, unlike Apios americana, the common peanut, and species in the genus Wisteria. It can be distinguished from various species of both Lathyrus and Vicia by the large stipules, which are larger than the basal leaflets (5).
Other members of the family in Michigan (number species): Amorpha (3), Amphicarpaea (1), Anthyllis (1), Apios (1), Astragalus (3), Baptisia (4), Caragana (1), Cercis (1), Chamaecrista (2), Colutea (1), Crotalaria (1), Cytisus (1), Dalea (3), Desmodium (14), Genista (1), Gleditsia (1), Glycin (1), Gymnocladus (1), Hedysarum (1), Kummerowia (1), Lathyrus (10), Lespedeza (14), Lotus (1), Lupinu (3), Medicago (4), Melilotus (2), Mimosa (1), Orbexilum (1), Phaseolus (2), Pisum (1), Robinia (3), Securigera (1), Senna (2), Strophostyles (1), Tephrosia (1), Trifolium (11), Vicia (9), Vigna (1), Wisteria (2)
Ethnobotanical Uses: Pisum sativum is a global food crop, including edible-pod peas as well as field and garden peas (2). Its seed, especially the oils, may be contraceptive. Powdered seed can also treat skin irritation and acne (3). Flowers are edible in a raw state (8). The top 10-15 cm (4-6) inches of pea plants are used in salads, stir-fries, and as decorative garnishes as a traditional Indochinese crop (10). From research into pea vine edibility comes the following wisdom: Remove tendrils before cooking/preparing pea vines as a vegetable. Taiwanese saying: “tendrils tie your tongue” (10).
Phylogenetic Information: Pisum sativum is one of only two species in the genus Pisum. Pisum is a Papilionoid genus in the Fabaceae, subfamily Faboideae. Families Fabaceae, Polygalaceae, Quillajaceae, and Surianaceae form the Fabales order. The Fabales, Rosales, Cucurbitales, and Fagales form a monophyletic group within the eurosids I inside the rosids. They are eudicots and angiosperms (4).
Interesting Quotation or Other Interesting Factoid not above:
- Vegetative, floral, and fruit morphology of Pisum sativum vary greatly.
- Plants are largely self-pollinated and thus it is easy to generate pure-breeding lineages.
- Gregor Mendel used peas as his model organism for his pioneering experiments in heredity. Using traits like pod color, seed shape, and plant height on this very species he began to understand how genetic information is passed from parent to progeny. (9)
- Peas are a target for genetic modification by incorporation of genes that combat a leaf fungus detrimental to pea crops. CSIRO in Australia has been involved (12)
Literature and websites used:
- USDA Plants Profile, http://www.nrcs.usda.gov/
- Purdue University Horticulture and Landscape Architecture. http://www.hort.purdue.edu/newcrop/cropfactsheets/pea.html.
- Plants for a Future database. http://www.pfaf.org/database/plants.php?Pisum+sativum
- ANGIOSPERM PHYLOGENY GROUP 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4):399-436.
- Voss, E.G. 1985. Michigan Flora Part II. Ann Arbor, Michigan, USA: University of Michigan Press.
- Fernald, M.L. 1950. Gray’s Manual of Botany, 8th ed. New York, USA: American Book Company.
- Charters, M.L. 2007. California Plant Names: Latin and Greek Meanings and Derivations A Dictionary of Botanical Etymology. http://www.calflora.net/botanicalnames/
- Badertscher, K.B. and S.E. Newman 2003. Edible Flowers. Colorado State University Cooperative Extension – Horticulture, no. 7.237 http://www.ext.colostate.edu/pubs/Garden/07237.html#top updated June 29, 2006.
- Travis, J. 1999. Monk learns secrets of heredity from pea plants. Science News 156(25 & 26): http://www.sciencenews.org/pages/sn_arc99/12_18_99b/fob9.htm
- Miles, C.A., R. Nakatani and M. Musick 2004. Pea Vine Production and Marketing Study. Washington State University Crop Production Vegetable Research and Extension. Updated May 26, 2004. http://vegetables.wsu.edu/peareport.htm
- Duke, J.A. 1981. Handbook of legumes of world economic importance. New York, New York, USA: Plenum Press. p. 199-265
- Higgins, T.J. 1998 PR-96” Field Evaluation of transgeneic lines of field pea (Pisum sativum L.) for resistance to Ascochyta blight. From Australia Office of Gene Technology Regulator Website www.ogtr.gov.au/pdf/volsys/pr96.pdf
- Leubner, G. Lab Website The Seed Biology Place. University Freiburg, Germany last updated 1 April, 2007; http://www.seedbiology.de/structure.asp
- Flora of Pakistan www.efloras.org http://efloras.org/florataxon.aspx?flora_id=5&taxon_id=125615
- Press, J.R., K.K. Shrestha, and D.A. Sutton 2000. Online update of Annotated Checklist of the Flowering Plants of Nepal (The Natural History Museum, London). http://efloras.org/flora_page.aspx?flora_id=110
- Bao, B. & N.J. Turland 2010. Flora of China, Vol. 10. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200012282
Image Credits (all used with permission):
1) Image of maturing fruits by Wikipedia User Rasbak, available online at http://commons.wikimedia.org/wiki/Pisum_sativum
2) Image of flower © Gerhard Bock (<http://www.bambooandmore.info> ).
3) Image of leaflets and tendrils copyright INRA with permission from Institut National de la Recherche Agronomique (France) http://www.inra.fr/legumineuses/accueil
4) Image of flower back and side: www.csdl.tamu.edu/FLORA/imaxxfab.htm
5) Image of Plate from Flora von Deutschland (last page of webpage) © 1999, Kurt Stüber, MPI für Züchtungsforschung also from www.csdl.tamu.edu/FLORA/imaxxfab.htm
6) Image of seedling by Lynn Kirkpatrick, Matthaei Botanical Garden, displayed with permission.
7) Species distribution map, derived from the Michigan Flora Online.
Primary Authors: Robyn J. Burnham, Susu Yuan, Marko Melymuka, John Bradtke, and Jenna Dorey
© Robyn J. Burnham, University of Michigan
For additional information on Michigan Plant Diversity web pages please contact Robyn J. Burnham via email: rburnham“at”umich.edu