Lathyrus japonicus (Beach Pea)

Plant Info
Also known as:
Genus:Lathyrus
Family:Fabaceae (Pea)
Life cycle:perennial
Origin:native
Habitat:part shade, sun; sandy soil, mostly lake shores
Bloom season:June - August
Plant height:1 to 2 feet
Wetland Indicator Status:none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: irregular Cluster type: raceme

[photo of flowers] Tight cluster of 6 to 10 pea-shaped flowers at the end of long smooth stem arising from the upper leaf axils, the flower stem shorter than the stem of the attending compound leaf. Flowers are ½ to ¾ inch long, about 3/8 inch across, the upper petal (standard) flaring out on the sides, rich purple with darker veination. The pale violet to white lateral wings below it enclose a small light lavender keel underneath. The calyx holding the flower is attached to a short stalk, both are smooth.

Leaves and stem: Leaf attachment: alternate Leaf type: compound

[photo of leaves] Leaves are compound with 3 to 6 leaflet pairs and a branched tendril at the tip, the compound leaves alternately attached along the stem and the leaf stalks distinctly arching. Leaflets are 1 to 2 inches long and about half as wide, oval to elliptic, narrowed at both ends. A pair of leafy appendages (stipules) nearly as large as the leaflets attend the leaves at the base of the leaf stalk; they resemble a pair of stalkless, opposite arrowhead-shaped leaves. Stems are angled and unbranched, with multiple stems arising from rhizomatous root system, forming dense clumps.

Fruit: Fruit type: capsule/pod

[photo of fruit] Fruit is a smooth flat pod, 1½ to 3 inches long and nearly ½ inch wide.

Notes:

Beach Pea is a circumboreal species and can be found along the Pacific coast of North America and throughout parts of Asia and Europe. In Minnesota it is mostly restricted to Superior's north shore with a few inland locations. Its low growth, arching branches and deep pinkish purple flowers are easily recognizable; the only pea type flower it can be mistaken for is the widely distributed Veiny Pea, Lathyrus venosus, whose flowers are nearly identical, but Veiny Pea is a much larger plant, typically to 3 feet tall with more than 10 flowers in a cluster and much smaller stipules with acutely angled tips. Veiny Pea can be found in a variety of habits throughout much of the state. Beach Pea would be an interesting species to try in a sandier garden site though probably would not perform well in hot locations. There are at least two subspecies (or varieties, depending on the reference) of Lathyrus japonicus but they are poorly documented. The species in Minnesota is subsp. maritimus, formerly known as Lathyrus maritimus var. glaber.

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens
  • Out Back Nursery
  • Shop for native seeds and plants at PrairieMoon.com!

More photos

Photos by K. Chayka taken at Flood Bay, Lake County. Photos by Peter M. Dziuk taken along Highway 53 north of Duluth, and in Cook and Lake counties.

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Mary - Kodunce sate wayside Cook county
on: 2021-07-14 20:06:06

Growing in pebble beach edge

Post a comment

Note: All comments are moderated before posting to keep the spammers out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.



(required)




Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because I’d like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.