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hairy bird's-foot trefoil

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

Habit Herbs annual, 7–25[–100] cm, hirsute; taprooted. Herbs annual or perennial, 5–70 cm, glabrous or sparsely pilose to strigose; usually taprooted, rarely rhizomatous.
Stems

erect to decumbent, solid, not succulent.

ascending or prostrate, solid, not succulent.

Leaves

8–15[–25] mm;

rachis 2–4 mm;

leaflet blades: basal 2 ovate, terminal 3 obovate to oblong or lanceolate, 5–10[–20] × 1–5.5[–8] mm, length 2–4 times width, apex acute to obtuse, often mucronate.

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.

Inflorescences

(1 or)2–4(–6)-flowered;

bracts 3-foliolate.

(1–)3–8(–10)-flowered;

bracts (1–)3-foliolate.

Peduncles

ascending to declined, 0.7–3[–15] cm.

decumbent to erect, 1.5–12 cm.

Flowers

5.5–7[–10] mm;

calyx 3.3–4.7 mm, lobes not recurved in bud, linear, 2.5–3.2 mm, longer than tube, tube hirsute;

petals yellow, turning reddish, 5–6.7[–10] mm, wings shorter than angled and beaked keel.

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.

Legumes

brown, cylindric, 7–10 × 0.7–1.2 mm, not or partially septate.

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

Seeds

8–10, brown to greenish brown, ± mottled, globose to round-oblong, 1 mm, smooth.

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

2n

= 12, 24 (Europe).

= 24.

Lotus subbiflorus

Lotus corniculatus

Phenology Flowering summer. Flowering summer.
Habitat Moist roadside ditches. Open, often wet disturbed, ruderal sites, lawns, fields, roadsides.
Elevation 40–200 m. (100–700 ft.) 0–1800 m. (0–5900 ft.)
Distribution
from FNA
OR; w Europe; n Africa (Algeria); Atlantic Islands (Azores) [Introduced in North America; introduced also in South America (Argentina), Pacific Islands (Hawaii, New Zealand), Australia]
[BONAP county map]
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]
Discussion

Lotus subbiflorus is easily distinguished by its very hirsute foliage and its sharply angled, beaked keel that is longer than the wings.

The introduced Lotus subbiflorus was collected first in 2009 at four locations in Curry County. The taxon is introduced elsewhere in the world, reported under the names L. hispidus, L. subbiflorus, or L. suaevolens (R. P. Randall 2002); when plotted worldwide, reports of L. hispidus and L. subbiflorus have similar overall distributions. Thus, it seems that in areas outside the native range, only a single entity is present that should be called L. subbiflorus.

The name Lotus hispidus Desfontaines (1804) was considered an invalid name by T. E. Kramina (2006). Kramina, however, appears to have been unaware of the subsequent validation of the name by de Candolle: L. hispidus Desfontaines ex de Candolle in J. Lamarck and A. P. de Candolle, Fl. Franç. ed. 3, 4: 556. 17 Sep 1805. The exact publication date of the name L. subbiflorus by Lagasca, however, is not known, but it may have been late in 1805 because Varied. Ci. 2(4) has 6 numbers (19–24) that were issued in 1805, and the name was published in number 22. Without an exact date for that publication, it is not possible to decide which name has priority, and currently the name L. subbiflorus is adopted for the species.

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

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.)

Source FNA vol. 11. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae > Lotus Fabaceae > subfam. Faboideae > Lotus
Sibling taxa
L. angustissimus, L. corniculatus, L. krylovii, L. tenuis, L. uliginosus
L. angustissimus, L. krylovii, L. subbiflorus, L. tenuis, L. uliginosus
Synonyms L. hispidus, L. suaevolens
Name authority Lagasca: Varied. Ci. 2(4): 213. (1805) Linnaeus: Sp. Pl. 2: 775. (1753) — (as corniculata)
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