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bird's-foot trefoil, birdfoot trefoil, common bird's-foot trefoil, garden bird's-foot-trefoil

krylov's bird's-foot trefoil, krylov's trefoil

Habit Herbs annual or perennial, 5–70 cm, glabrous or sparsely pilose to strigose; usually taprooted, rarely rhizomatous. Herbs perennial [annual], 10–45 cm, glabrous (except glabrate on leaves and calyx); taprooted.
Stems

ascending or prostrate, solid, not succulent.

erect or decumbent, solid, not succulent.

Leaves

5–30 mm;

rachis (1–)2–10 mm;

leaflet blades sometimes asymmetric, obovate to oblanceolate, oblong, or ovate, 4–22 × 2–11 mm, length 1.6–3(–4) times width, apex obtuse and mucronate or acuminate.

8–16 mm;

rachis 1.5–5 mm;

leaflet blades: basal 2 obliquely ovate, terminal 3 obovate to obovate-elliptic or obovate-lanceolate, 5–15 × 1–4 mm, length 3.2–5 times width, apex rounded to ± acute.

Inflorescences

(1–)3–8(–10)-flowered;

bracts (1–)3-foliolate.

1(or 2[–4]-flowered;

bracts 1–3-foliolate.

Peduncles

decumbent to erect, 1.5–12 cm.

ascending, 1–4.5(–6) cm.

Flowers

10–17 mm;

calyx 5–7.5 mm, lobes not recurved in bud, usually triangular, rarely ovate, (1.5–)2.5–4.5 mm, shorter to slightly longer than tube, tube villous;

petals bright yellow, marked with red, turning orange, 8–14 mm, wings shorter to longer than keel.

7–9.2[–10] mm;

calyx 4–6 mm, lobes erect in bud, triangular to deltate-acuminate, (1.5–)2–2.8[–3.5] mm, ± equaling tube, tube glabrate;

petals light yellow, ± pink-tinged abaxially, turning pinkish or red, 6.6–8.5 mm, wings equaling keel.

Legumes

brown, narrowly oblong, 15–35 × 2–3 mm, not septate.

brown, cylindric, 15–25[–35] × 2–3 mm, not septate.

Seeds

5–30, yellowish or light to dark brown, mottled or sometimes not, globose to round-oblong, 1–1.7 mm, smooth.

6–10[–30], brown, finely mottled, globose, 0.8–1.4 mm, smooth.

2n

= 24.

= 12.

Lotus corniculatus

Lotus krylovii

Phenology Flowering summer. Flowering summer.
Habitat Open, often wet disturbed, ruderal sites, lawns, fields, roadsides. Alkaline meadows, saline lake shores, dry hillsides.
Elevation 0–1800 m. (0–5900 ft.) 500–600 m. (1600–2000 ft.)
Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; GA; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; YT; SPM; Eurasia; n Africa [Introduced also in Mexico, Central America, South America, Atlantic Islands (Iceland), Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
BC; e Europe (Russia, Ukraine); c Asia; w Asia [Introduced in North America]
[BONAP county map]
Discussion

Lotus corniculatus has been widely introduced both as a forage crop and for roadside stabilization throughout North America. M. D. Ross and W. T. Jones (1985) presented evidence that L. corniculatus is an allotetraploid derived from the hybrid between either L. tenuis or L. alpinus (Seringe) Schleicher ex Ramond, as the pistillate parent, and L. uliginosus. This would explain the close morphological similarity with L. tenuis.

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

Lotus krylovii is known in the flora area only from the the Okanagan Valley of British Columbia, near White Lake. I. I. Zandstra and W. F. Grant (1968) reported it in their study of Lotus in Canada, and it is still extant there.

S. I. Ali (1977) synonymized this species with an expanded Lotus corniculatus var. tenuifolius Linnaeus (synonym of L. tenuis), but the taxa are distinct in morphology, distribution, and ecology.

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

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Lotus Fabaceae > subfam. Faboideae > Lotus
Sibling taxa
L. angustissimus, L. krylovii, L. subbiflorus, L. tenuis, L. uliginosus
L. angustissimus, L. corniculatus, L. subbiflorus, L. tenuis, L. uliginosus
Synonyms L. corniculatus var. versicolor
Name authority Linnaeus: Sp. Pl. 2: 775. (1753) — (as corniculata) Schischkin & Sergievskaja: Sist. Zametki Mater. Gerb. Tomsk. 1932(7–8): 5. (1932)
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