E-Flora BC: Electronic Atlas of the Flora of British Columbia

Lathyrus littoralis (Nutt.) Endl.
grey beach peavine (dune sweet pea; silky beach pea)
Fabaceae (Pea family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #20374)

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Distribution of Lathyrus littoralis
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Introduction

Silky beach pea is a perennial rhizomatous member of the pea family (Fabaceae) that is found in North America in coastal dunes and beaches only along the Pacific Coast (British Columbia, Washington, Oregon and California) (USDA 2011). In British Columbia, this is a red-listed species that is found in only a few locations on Vancouver Island (Saanich Peninsula) and the adjacent Gulf Islands (Sidney Spit), and on Haidai Gwaii. There is one report from Swishwash Island in the mouth of the Fraser River. Plants are prostrate to erect, flowers are a striking combination of purple and white, and leaves are alternate and pinnately compound with 4-8 leaflets. The plant is densely silky-grey, with silky-grey pods.

Although rare in British Columbia, this is a salt-tolerant species that is used in revegetating shoreline areas in the U.S. In BC, it has now been reported from the following BEC zones: CDFmm, CWHvh, CWHwh, CWHxm (BCCDC 2012).

Species Information

Click on the image below to view an expanded illustration for this species.



General:
Perennial herb from a wide-spreading rhizome; stems prostrate to erect, 10-60 cm long, angled but not winged, densely grey-silky.
Leaves:
Alternate, pinnately compound with 4 to 8 leaflets; leaflets oblong-lanceolate, 1-2 cm long, grey-silky, the axis 1.5-3 cm long, flattened and prolonged as a broad bristle but not tendril-like; stipules egg- to arrowhead-shaped, equal to or larger than the leaflets, sometimes constricted into upper and lower lobes.
Flowers:
Inflorescence a loose, long-stalked, axillary cluster of 2 to 6 pea-like flowers; corollas 12-18 mm long, the banner pink or red to purple (rarely white), 14-18 mm long, the banner-claw 2/3 as long as the blade, the wings and keel usually white, shorter than the banner; calyces 8-11 mm long, the lanceolate teeth nearly equal in size and about as long as the tube.
Fruits:
Pods, 3 cm long, 1 cm wide, grey silky-hairy; seeds 1 to 5.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Purple
Blooming Period:
Spring
Fruit/Seed characteristics:
Colour: Black
Present from Spring to Summer
Source:  The USDA

Habitat / Range

Coastal dunes and sand beaches; infrequent, scattered on Vancouver Island and the Queen Charlotte Islands; S to N CA.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Lathyrus littoralis

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Minimum

Average

Maximum

Elevation (metres) 2 5 11
Slope Gradient (%) 0 0 1
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 2 4
Modal Nutrient Regime
Class
A
Number of field plots
 species was recorded in:
3
Modal BEC Zone Class
CWH
All BEC Zones (# of stations/zone) species was recorded in: CWH(3)

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

Species References

B.C. Conservation Data Centre. 2012. Species Summary: Lathyrus littoralis. B.C. Minist. of Environment. {ah}a100.gov.bc.ca/pub/eswp/ {/h}Available online{/h} (accessed Apr 30, 2012).

General References