Lathyrus japonicus
Lathyrus japonicus var. japonicus
beach or maritime or sand pea, beach pea, beach vetchling, maritime pea, sea pea, seaside pea
beach pea
angled to narrowly winged, erect, sprawling, or climbing, basally branched 0–4 times, 1–10 dm.
1–3.5 dm.
3–15 cm;
tendrils usually well developed, branched or unbranched;
stipules sagittate-ovate, 7–35 × 7–30 mm, as large as basal leaflets;
leaflets 6–12, usually scattered, blades ovate to lanceolate, 15–55 × 5–35 mm, surfaces glabrous throughout or pubescent abaxially.
3–7 cm;
tendrils unbranched, less than 3 cm;
leaflets 6–8, blades 15–35 × 5–15 mm, surfaces glabrous.
4–9-flowered, 4–15 cm.
12–29 mm;
calyx lobes unequal, lateral lobes linear-triangular, longer than tube;
corolla blue to purple, banner erect, blade longer than claw, wings equal to keel;
ovary eglandular and glandular-pubescent.
35–65 × 6–12 mm.
= 14.
Lathyrus japonicus
Lathyrus japonicus var. japonicus
Varieties 3 (3 in the flora).
Within Lathyrus japonicus, in the narrow sense, there is a south to north reduction in plant size, including plant height, robustness, and leaflet size, but not flower size, flower number, or fruit size. On the east coast of North America this shift seems fairly abrupt, giving the appearance of a clear distinction between var. maritimus and var. pellitus in the south, and var. japonicus to the north in Labrador and Greenland. However, on the West Coast, there are few truly pubescent forms (var. pellitus), and there seem to be many more intermediates between var. maritimus in the south and var. japonicus to the north.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Variety japonicus is a diminutive, low-growing form found most often on sandy or rocky beaches in arctic and subarctic regions.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stems 1–3.5 dm; leaflet blades 15–35 mm; tendrils unbranched, less than 3 cm. | var. japonicus |
1. Stems 3–10 dm; leaflet blades 30–50(–55) mm; tendrils branched, 3+ cm. | → 2 |
2. Leaflet blades glabrous. | var. maritimus |
2. Leaflet blades pubescent abaxially (especially new growth). | var. pellitus |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, Turner Photog. 
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USDA Plants Database- LBJ Wildflower Center
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MI Flora
