The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

gesse des marais, marsh pea, marsh peavine, marsh vetchling

two-flower pea, two-flower sweet pea

Habit Herbs perennial, from rhizome, glabrous or pubescent. Herbs perennial, from rhizome, villous.
Stems

narrowly to broadly winged, sprawling or climbing, basally branched 0–4 times, 2–10 dm.

angled, erect or sprawling, basally branched 1–3 times, 0.5–1 dm.

Leaves

1–6 cm;

tendrils well developed;

stipules ovate-lanceolate to linear, 5–25 × 1–10 mm, much smaller than leaflets;

leaflets 4–8, paired, blades lanceolate to linear, 15–75 × 2–20 mm, surfaces glabrous, glabrate, or pubescent.

0.5–1 cm;

tendrils absent or reduced to flattened bristles;

stipules linear, 4–5 × 1–2 mm, ca. 1/2 length of leaflets;

leaflets (3 or)4(or 5), paired, blades lanceolate, 6–12 × 2–3 mm, surfaces finely villous.

Inflorescences

2–7-flowered, 3–15 cm.

1- or 2-flowered, 1 cm.

Flowers

10–15 mm;

calyx lobes unequal, lateral lobes deltate, shorter than tube;

corolla blue-purple, banner erect, blade equal to claw, wings equal to keel;

ovary glandular-pubescent.

7–8 mm;

calyx lobes subequal, lateral lobes deltate, shorter than tube;

corolla cream, banner erect, blade equal to claw, wings equal to keel;

ovary glabrous.

Legumes

25–60 × 4–8 mm.

13–15 × 3–5 mm.

2n

= 14.

Lathyrus palustris

Lathyrus biflorus

Phenology Flowering Apr–Aug. Flowering Jun.
Habitat Coastal and inland wetlands. Serpentine outcrops and Jeffrey pine woodlands.
Elevation 0–1800 m. (0–5900 ft.) 1300–1400 m. (4300–4600 ft.)
Distribution
from FNA
AK; AL; AR; CA; CO; CT; DC; DE; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; ND; NE; NH; NJ; NY; OH; OR; PA; RI; SD; TN; VA; VT; WA; WI; WV; BC; MB; NB; NL; NS; NU; ON; PE; QC; SK; SPM
[WildflowerSearch map]
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

Morphological variation within Lathyrus palustris is extensive. Although the most distinctive forms (see synonyms) have been accorded formal nomenclatural recognition (M. L. Fernald 1911; C. L. Hitchcock 1952), intergradation among these mostly sympatric ecotypes is widespread (D. Isely 1998). In Nunavut, it is known only from Akimiski Island in James Bay.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Lathyrus biflorus is known only from southeastern Humboldt County.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Lathyrus Fabaceae > subfam. Faboideae > Lathyrus
Sibling taxa
L. angulatus, L. aphaca, L. biflorus, L. brachycalyx, L. brownii, L. cicera, L. decaphyllus, L. delnorticus, L. eucosmus, L. glandulosus, L. graminifolius, L. grimesii, L. hirsutus, L. hitchcockianus, L. holochlorus, L. japonicus, L. jepsonii, L. laetivirens, L. lanszwertii, L. latifolius, L. littoralis, L. nevadensis, L. nissolia, L. ochroleucus, L. odoratus, L. pauciflorus, L. polyphyllus, L. pratensis, L. pusillus, L. rigidus, L. sphaericus, L. splendens, L. sulphureus, L. sylvestris, L. tingitanus, L. torreyi, L. tracyi, L. tuberosus, L. venosus, L. vestitus
L. angulatus, L. aphaca, L. brachycalyx, L. brownii, L. cicera, L. decaphyllus, L. delnorticus, L. eucosmus, L. glandulosus, L. graminifolius, L. grimesii, L. hirsutus, L. hitchcockianus, L. holochlorus, L. japonicus, L. jepsonii, L. laetivirens, L. lanszwertii, L. latifolius, L. littoralis, L. nevadensis, L. nissolia, L. ochroleucus, L. odoratus, L. palustris, L. pauciflorus, L. polyphyllus, L. pratensis, L. pusillus, L. rigidus, L. sphaericus, L. splendens, L. sulphureus, L. sylvestris, L. tingitanus, L. torreyi, L. tracyi, L. tuberosus, L. venosus, L. vestitus
Synonyms L. myrtifolius, L. palustris var. linearifolius, L. palustris var. macranthus, L. palustris var. myrtifolius, L. palustris subsp. pilosus, L. palustris var. pilosus, L. palustris var. retusus
Name authority Linnaeus: Sp. Pl. 2: 733. (1753) T. W. Nelson & J. P. Nelson: Brittonia 35: 183, fig. 2. (1983)
Web links