Name: Lathyrus ochroleucus Hook.
Family: Fabaceae (the pea family)
Common Names: Yellow vetchling, Cream vetchling, Wild-pea, Pale vetchling, Pale vetchling peavine (1,3,8)
Etymology: Lathyrus is derived from the Greek word lathyros, which means a legume. Ochroleucous is derived from the Greek words ochros, meaning pale-yellow, leukos, meaning white, and osus, meaning having the nature or quality of (5).
Botanical synonyms: Lathyrus albidus Eaton, Lathyrus glaucifolius Beck, Orobus ochroleucus (Hook.) A. Brown, Lathyrus ochroleucus Torr. (12,13)
Quick Notable Features:
¬ Showy yellowish-white flowers in racemes
¬ Compound leaves with 3-5 pairs of leaflets
¬ Tendrils develop at the tip of leaf
¬ Slender, wingless stem
Plant Height: The plant generally grows up to 1 m (2,6).
Subspecies/varieties recognized: None found.
Most Likely Confused with: Among Fabaceae this can be confused with other species of Lathyrus, most species of the genus Astragalus (known as milk-vetch), species of Pisum, Vicia, Amphicarpaea, and Wisteria. In addition, it might be confused with the Ranunculaceae climber genus, Clematis.
Habitat Preference: Grows best in dry rocky woodlands, brushy ravines, stream valleys, and roadsides. It also prefers a sunny edged or slightly shaded area (1,2).
Geographic Distribution in Michigan: L. ochroleucus is scattered throughout the Upper and Lower Peninsula of Michigan, although it is mostly concentrated in the southeastern part of the state. In the Lower Peninsula it is found in the following counties: Alcona, Alpena, Bay, Berrien, Calhon, Cheboygan, Gladwin, Gratiot, Hillsdale, Ingham, Ionia, Iosco, Isabella, Jackson, Kalamazoo, Kent, Lapeer, Leelanau, Livingston, Montcalm, Oakland, Osceola, Oscoda, St. Clair, St. Joseph, Tuscola, Van Buren, Washtenaw, and Wayne. In the Upper Peninsula, it is found in Alger, Bois Blanc Island, Delta, Drummond Island, Gogebic, Keweenaw, Isle Royale, Mackinac, Marquette, Menominee, and Ontonagon (14).
Known Elevational Distribution: Specific elevation restriction has not yet been found in the literature, but its occurrence decreases with increasing elevation (15).
Complete Geographic Distribution: Native to the United States and Canada, Lathyrus ochroleucus exists within the US in and to the north of the following states: Idaho, Wyoming, Nebraska, Iowa, Illinois, Indiana, Ohio, Pennsylvania, and New Jersey. It does not exist in the states northeast of Vermont and New York. In Canada, it is present from Quebec to British Columbia (2,12).
Vegetative Plant Description: L. ochroleucus is a perennial herb with a slender, wingless stem. The stem is somewhat angled and can be up to 80cm long. At the base of the stem, there are two large leafy stipules that are up to half the size of the leaflets. The petioles are 1-3cm long. The leaves are alternate and pinnately divided into 3-5 pairs of glabrous, oval to ovate leaflets. The leaflets range in size from 2-5cm long and 1-4 cm wide. Tendrils are found at the terminus of the leaf-tip. The roots of L. ochroleucus have nodules that contain bacteria, which can fix atmospheric nitrogen (1,6, 7,10,18).
Climbing Mechanism: Lathyrus ochroleucus climbs with tendrils that develop at the end of each compound leaf, replacing the terminal leaflet position. The tendrils can be branched or simple (11,19).
Flower Description: The inflorescences are racemes mostly with 5-10 perfect flowers (with both male and female organs), each 1-2cm long. The 5 sepals and 5 petals are yellowish-white and the flower is zygomorphic (1,4,18). The lateral calyx lobes are ovate. Stamens are 9+1 and the superior ovary bears a single carpel with a flat style that is pubescent on the inner surface (6).
Flowering Time: In Ohio, L. ochroleucus flowers from May to July (3). In Minnesota it was reported as starting to flower in early June (20).
Pollinator: Flowers are pollinated by insects, the type unspecified (2).
Fruit Type and Description: The fruit is a sessile, glabrous legume, flat and long, measuring 4-5cm long and 4-6mm wide (1).
Seed Description: The seeds are olive to brown in color, smooth, and 3-3.5mm long (1).
Dispersal Syndrome: No information found.
Distinguished by: Lathyrus ochroleucus is distinguished from other Lathyrus species by its yellowish-white flowers. Most of the other species have flowers that are purple or pink. Additionally, L. latifolius has only 2 leaflets, compared to 6-10 in L. ochroleucus. The fruit of L. odoratus and L. hirsutus is pubescent, whereas the fruit of L. ochroleucus is glabrous. L. ochroleucus is distinguished from species of Astragalus because L. ochroleucus lacks hairs on the stem and fruit. Species of Astragalus usually have more than 10 leaflets, compared to 6-10 in L. ochroleucus. L. ochroleucus can be distinguished from species of Clematis since Clematis includes species that have opposite, compound leaves and lobed, coarsely toothed leaflets. The fruit of Clematis is a flat achene, arranged in a dense cluster, instead of a legume (4).
Members of the family in Michigan (number species): Amorpha (2), Amphicarpaea (1), Anthyllis (1), Apios (1), Astragalus (3), Baptisia (4), Caragana (1), Cercis (1), Chamaecrista (2), Cladrasis (1),Colutea (1), Crotalaria (1), Cytisus (1), Dalea (1), Desmodium (12), Genista (1), Gleditsia (1), Glycine (1), Gymnocladus (1), Hedysarum (1), Kummerowia (1), Lathyrus (9), Lespedeza (13), Lotus (1), Lupinus (2), Melilotus (2), Mimosa (1), Orbexilum (1), Phaseolus (2), Pisum (1), Pueraria (1), Robinia (3), Securigera (1), Senna (1), Strophostyles (1), Tephrosia (1), Trifolium (9), Vicia (8), Vigna (1), Wisteria (1) (8,14).
Ethnobotanical Uses: The plant has been used to treat stomach aches. The leaves and roots have been fed to ponies before races by Ojibwe Indians into order to enhance the pony’s spirit and make it livelier. The Ojibwe Indians also eat the seeds and roots (2,9).
Phylogenetic Information: Fabaceae belongs to the order Fabales, which is closely related to Fagales, Cucurbitales, and Rosales within the clade, Eurosids I. Within Fabaceae, L. latifolius belongs to the subfamily, Faboideae (also known as Papilionoideae). Members of this subfamily are characterized by the papilionaceous flowers. L. latifolius is included in the Fabaceous tribe Fabeae (also known as Vicieae and thus close to the genus Vicia) (12,16,17).
Interesting Quotation or Other Interesting Factoid not inserted above:
“Many plants of this genus [Lathyrus] are eaten by livestock and have been used successfully in various parts of the world. However, they are generally viewed with suspicion because some cause a type of poisoning called lathyrism, which results from eating too much vetchling seed over long periods of time. Epidemics of lathyrism date back to ancient Greece, but cases in humans usually occurred during famines when people were forced to eat vetchling almost exclusively. After 10 days to 4 weeks, this can cause progressive loss of coordination, ending in irreversible paralysis. Vetchling is not generally considered poisonous but these plants should be approached with caution” (11).
Literature and websites used:
- McGregor R.L. 1986. Flora of the Great Plains. Lawrence, Kansas, USA: The University Press of Kansas.
- Plants For a Future, 1996-2008. http://www.pfaf.org/database/plants.php?Lathyrus+ochroleucas (1/14/10)
- Burns, J. 1982. Ohio Department of Natural Resources
- Gleason, H. A. 1963. Illustrated Flora of the Northeastern United States and Adjacent Canada, Volume 2. New York, New York, USA: Hafner Publishing Company, Inc.
- Brown, R. W. 1956. Composition of Scientific Words. Washington, D.C., USA: Smithsonian Institution Press.
- Fernald, M. L. 1950. Gray’s Manual of Botany, 8th ed. New York, USA: American Book Company.
- Parkhurst, H.E. 1903. Trees, shrubs and vines of the northeastern United States. New York, New York, USA: C. Scribner’s Sons.
- USDA Natural Resources Conservation Service Plant Database.. http://plants.usda.gov/java/profile?symbol=LAOC2 (1/14/10)
- Native American Ethnobotany Database. http://herb.umd.umich.edu/herb/search.pl?searchstring=Lathyrus%20ochroleucus&searchlimit=100 (1/14/10)
- http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=LATOCH (1/20/10)
- http://www.borealforest.org/herbs/herb19.htm (1/20/10)
- ILDIS Legumes of the World http://www.ildis.org/LegumeWeb/6.00/taxa/11474.shtml (1/14/10)
- International Plant Names Index (IPNI) http://www.ipni.org/index.html (1/20/10)
- Voss, E. G. 1985. Michigan Flora Part II: Dicots. Ann Arbor, Michigan, USA: Cranbrook Institute of Science.
- Ceska, A., Klinka, K., Krajina, V., Scagel, A. 1989. Indicator Plants of Coastal British Columbia. Vancouver, British Columbia: UBC Press.
- USDA Germplasm Resources Information Network.
- http://www.ars-grin.gov/cgi- bin/npgs/html/taxon.pl?21580 (1/20/10)
- Stevens, P.F. 2001 onwards. Angiosperm Phylogeny Website. Version 7, May 2006.
- http://www.mobot.org/MOBOT/research/APweb/welcome.html (1/20/10)
- Erichsen-Brown, Charlotte. 1979. Medicinal and Other Uses of North American Plants. Toronto, Canada: General Publishing Company.
- Tillman, O. 1905. Ohio Plants with Tendrils. The Ohio Naturalist 5(5): 306.
- Chayka, K. and P. M. Dziuk 2006-2010. 20). Wildflowers http://www.minnesotawildflowers.info/flower/cream-pea
Image Credits (all used with permission):
1) Images of flowers: http://www.minnesotawildflowers.info/flower/cream-pea
2) Images of leaves: http://www.minnesotawildflowers.info/flower/cream-pea
3) Flower close-up: Andy Fyon, ontariowildflower.com: http://www.ontariowildflower.com
4) Species distribution map, derived from the Michigan Flora Online.
Primary Authors: Andrea Friedmann, with edits by John Bradtke, Robyn J. Burnham, and Cristine V. Santanna
© 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