Lathyrus japonicus Willd.
beach pea (sea pea; sea vetchling)
Fabaceae (Pea family)

Introduction to Vascular Plants

Photograph

© Virginia Skilton     (Photo ID #3378)


Map

E-Flora BC Static Map

Distribution of Lathyrus japonicus
Click here to view the full interactive map and legend

SUBTAXA PRESENT IN BC

Lathyrus japonicus var. maritimus

Introduction

Beach pea is a perennial, rhizomatous herbaceous species that is circumboreal in distribution. It is "widely distributed on coasts of temperate Asia, Europe, North America, and South America (Chile)" (Flora of China 2011). In North America, this includes the coastal areas of the Great Lakes. In British Columbia, it ranges along the Pacific coast from Vancouver to just north of Prince Rupert. This low growing, blue/pink/purple flowering species trails or climbs in well-drained sandy habitats proximal to the ocean (sandy coastal areas/foredunes), in dynamic drift areas or on stabilized foredunes. Leaves are alternate and pinnately compound with 6-10 leaflets, stems are not winged, and pods are hairy. Flowers are often two-coloured and are in racemes of 2-7.

Beach Pea is an ecologically and biogeographically interesting species. Plants are reported to flower in their third year, with pollination by long-tongued bumblebees (Low 2005). Seeds of this species disperse in sea water and may remain viable for up to 5 years, which may aid in long-distance dispersal (Wikipedia 2011).

A detailed description of this species is provided in the Flora of China online.Beach pea is a perennial, rhizomatous herbaceous species that is circumboreal in distribution. It is "widely distributed on coasts of temperate Asia, Europe, North America, and South America (Chile)" (Flora of China 2011). In North America, this includes the coastal areas of the Great Lakes. In British Columbia, it ranges along the Pacific coast from Vancouver to just north of Prince Rupert. This low growing, blue/pink/purple flowering species trails or climbs in well-drained sandy habitats proximal to the ocean (sandy coastal areas/foredunes/foredune grasslands), in dynamic drift areas or on stabilized foredunes. Leaves are alternate and pinnately compound with 6-10 leaflets, stems are not winged, and pods are hairy. Flowers are often two-coloured and are in racemes of 2-7.

Beach Pea is an ecologically and biogeographically interesting species. Plants are reported to flower in their third year, with pollination by long-tongued bumblebees (Low 2005). Seeds of this species disperse in sea water and may remain viable for up to 5 years, which may aid in long-distance dispersal (Wikipedia 2011).

A detailed description of this species is provided in the Flora of China online.

Species Information

General:
Perennial herb from a rhizome; stems trailing to climbing, 10-150 cm long, angled or flanged but not winged, glabrous to short-hairy.
Leaves:
Alternate, pinnately compound with 6 to 12 leaflets; leaflets paired or scattered, egg-shaped to oblong, 1-7 cm long, 0.5-4 cm wide, rather fleshy, strongly veined when dry; tendrils well developed, grasping or branched or neither; stipules large, leafy, obliquely arrowhead-shaped, about as long as the leaflets.
Flowers:
Inflorescence a loose, stalked, axillary cluster of 2 to 8 pea-like flowers; corollas reddish-purple to blue, often 2-coloured, up to 3 cm long, the wings and keel shorter than the banner, the banner-claw equal to the blade; calyces 10-15 mm long, the teeth lanceolate, the upper pair 1/2 as long as the lateral pair which are 1-2 mm shorter than the lowest one, all three of the lower teeth longer than the tube.
Fruits:
Pods, usually hairy, 3-7 cm long, 1 cm wide; seeds 5 to16.

SourceThe Illustrated Flora of British Columbia

USDA Species Characteristics

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

Ecology

Ecological Framework for Lathyrus japonicus

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

Avg

Min

Max

Elevation (metres)
8 0 15
Slope Gradient (%)
1 0 3

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

207 135 280
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 2 2
Modal Nutrient Regime
Class
A
# of field plots
 species was recorded in:
5
Modal BEC Zone Class
CWH

All BEC Zones (# of stations/zone) species was recorded in

CWH(5)

Habitat and Range

Sandy or gravelly beaches (often amongst driftwood), dunes, rocky headlands in the lowland zone; common in coastal BC; circumboreal, N to AK, E to NF and S to N CA; Eurasia, Chile.

SourceThe Illustrated Flora of British Columbia