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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

redwood pea, Torrey's pea, Torrey's peavine

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

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

angled, erect to sprawling, basally branched 0–3 times, 1–4 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.

2–7 cm;

tendrils absent or mucronate;

stipules lanceolate, 7–12 × 2–5 mm, much smaller than leaflets;

leaflets 8–16, scattered, blades ovate to lanceolate, 5–15 × 3–10 mm, surfaces villous.

Inflorescences

2–6-flowered, 2–10 cm.

1- or 2-flowered, 0.5–3 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.

8–12 mm;

calyx lobes unequal, lateral lobes linear-triangular, longer than tube;

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

ovary densely pubescent.

Legumes

25–45 × 6–10 mm.

15–20 × 4–5 mm.

2n

= 14.

Lathyrus lanszwertii

Lathyrus torreyi

Phenology Flowering Apr–Jul.
Habitat Open coniferous forests.
Elevation 50–1500 m. (200–4900 ft.)
Distribution
from USDA
w North America
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR; WA
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 5 (5 in the flora).

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

Lathyrus torreyi is known from in and west of the Cascade Range; it is very rare in Washington.

(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
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. sulphureus, L. sylvestris, L. tingitanus, 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
Name authority Kellogg: Proc. Calif. Acad. Sci. 2: 150, fig. 44. (1863) A. Gray: Proc. Amer. Acad. Arts 7: 337. (1868)
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