Alfalfa Chilota / Greater Bird's-foot Trefoil

Here's a translation I got from an online source (Microsoft Translator), not totally accurate, but at least it's a start. I made a few modifications of the translation to help it make more sense. (One translation gave "puff pastry" for "leaves." Perennial herb spreading by Rhizomes. Stems ascending, hollow, more or less branched up to 1 m leaves composed by 5 leaflets up to 2.5 cm, verdiazules below, being the two lower resembling stipules. Flakes of contour rhomboidal or obovate, acute, entire, variously hairy, up 25 x 15 mm. Flowers arranged in heads or crowns of long bars in number between 5 and 12; tubular calyx, acampanado with 5 teeth extended outbreak, approximately the length of the tuco. Corolla amariposada yellow, often dyed red, between 1 and 1.8 cm in length. Fruit pod up to 35 x 2.5 mm in length. It flowers in spring and summer. Habitat: L. pedunculatus appears in a wide range of habitats wet and open, showing a slight predilection for the acidic soils. Thus, you can find in grassland, subtropical wet, with ponds, lakes or rivers or wetlands such as marshes and wetlands. Notes: This species has the same properties as the cuernecillos: infusion of the flowers helps combat insomnia.

Con más fotos podría saber, pero me tinca que es Lotus uliginosus

Looks like something in the Lotaea tribe.