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aspen peavine, lanszwert's pea, lanszwert's vetchling, Nevada pea, Nevada peavine, Nevada sweet pea, pinewood peavine, Rocky Mountain sweetpea, thick-leaf pea, thick-leaf peavine

Brewer's sweet or snub or sulfur pea, Brewer's sweet pea, snub pea, sulfur pea, sulpher pea, sulphur pea

Habit Herbs perennial, from rhizome, glabrous or sparsely pubescent. Herbs perennial, from rhizome, usually glabrous, rarely pubescent.
Stems

angled, erect, sprawling, or climbing, basally branched 0–4 times, 1–8 dm.

angled, climbing, basally branched 0–3 times, 5–15 dm.

Leaves

(0.5–)1–8 cm;

tendrils mucronate to well developed;

stipules linear to lanceolate, 5–25 × 1–6 mm, much smaller than leaflets;

leaflets 2–10, scattered, blades lanceolate or linear, 20–70 × 2–20 mm, surfaces glabrous or sparsely pubescent.

9–12 cm;

tendrils well developed;

stipules lanceolate, 15–25 × 4–10 mm, sometimes equal to distal leaflets;

leaflets 6–12, scattered, blades ovate to lanceolate, 25–50 × 10–20 mm, surfaces glabrous or pubescent.

Inflorescences

2–6-flowered, 2–10 cm.

9–15-flowered, 6–10 cm.

Flowers

7–15 mm;

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

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

ovary glabrous.

11–13 mm;

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

corolla orange to yellow-cream, banner erect, blade shorter than claw, wings equal to keel;

ovary glabrous.

Legumes

25–45 × 6–10 mm.

40–70 × 4–6 mm.

Lathyrus lanszwertii

Lathyrus sulphureus

Distribution
from USDA
w North America
[WildflowerSearch map]
[BONAP county map]
from USDA
w United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 5 (5 in the flora).

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

Varieties 2 (2 in the flora).

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

Key
1. Stems (2–)3–8 dm, usually climbing, sometimes sprawling or erect; tendrils well developed, usually branched.
→ 2
2. Leaflets 8–10; corollas blue-purple; California northward to Washington, eastward to Colorado and Wyoming.
var. lanszwertii
2. Leaflets 6–8; corollas white; w Colorado, c Utah, Wyoming.
var. pallescens
1. Stems 1–3(–4) dm, usually erect (sometimes var. bijugatus sprawling or climbing); tendrils reduced to simple bristles less than 1 cm.
→ 3
3. Leaflets 2–4; e Washington, adjacent Idaho, Montana, British Columbia.
var. bijugatus
3. Leaflets 4–8; California northward to sc Washington and eastward to New Mexico, Colorado, and Wyoming.
→ 4
4. Flowers 7–10 mm; California, Nevada, Oregon, Washington.
var. aridus
4. Flowers 10–15 mm; Arizona, Colorado, New Mexico, Utah, Wyoming.
var. leucanthus
1. Herbs glabrous.
var. sulphureus
1. Herbs densely villous.
var. argillaceus
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. 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
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. palustris, L. pauciflorus, L. polyphyllus, L. pratensis, L. pusillus, L. rigidus, L. sphaericus, L. splendens, L. sylvestris, L. tingitanus, L. torreyi, L. tracyi, L. tuberosus, L. venosus, L. vestitus
Subordinate taxa
L. lanszwertii var. aridus, L. lanszwertii var. bijugatus, L. lanszwertii var. lanszwertii, L. lanszwertii var. leucanthus, L. lanszwertii var. pallescens
L. sulphureus var. argillaceus, L. sulphureus var. sulphureus
Name authority Kellogg: Proc. Calif. Acad. Sci. 2: 150, fig. 44. (1863) W. H. Brewer ex A. Gray: Proc. Amer. Acad. Arts 7: 399. (1868)
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