Trifolium repens L.
White clover, Dutch clover.
Fabáceae (Papilionáceae) – Pea family.
Leaves: Trifoliate and long-stalked; leaflets very narrow oval to oval, very finely toothed, up to 4 cm long, rounded or somewhat incised, smooth and sometimes with a white mark in the middle.
Inflorescense: Racemose heads 15-20 mm across with many flowers.
Flowers: With distinct stems ; 5 fused sepals, covered thickly with hairs, lightly coloured in the lower part and mid to dark green at the long teeth, often with a reddish overlay ; calyx tube has gren veins ; 5 petals, white to pale reddish, 6-12 mm long, fused to form two narrow wings, a keel and a standard swelling outwards a little ; 10 stamens, superior ovary 2 carpels.
Perrennials with creeping stems rooting at the nodes; flowering until September.
Trifolium pratense L.
Fabáceae (Papilionáceae) Pea Famiy
Leaves: Ternate, on stems ; leaflets oval, blunt ended, round, rather pointed or shallowly notched at tips, usually entire, often with lighter green, whitish or reddish markings, somewhat hairy and up to 3 cm. long.
Inflorescence: Egg-shaped or spherical raceme, solitary or in small groupsat ends of stem or branches
Flowers: 5 fused sepals, whitish-green and rather hairy, with thread like greenish points: 5 red petals 5 times as long as the calyx tube (10-15mmlong); standard significantly longer than wings or keel: 10 stamens ; superior ovary ; fertilised by insects.
Usually perennial with upright stems; flowering from May to October
Medicago lupulina L
Fabáceae (Papilionáceae) Pea Family
Leaves: The 3 leavelets are oval or rhomboid, finely toothed, especially in the upper part, with scattered close hairs and blunt-ended or rather flat ; topmost leaflet has a stalk and is often rather larger than the latreal ones.
Inflorescence: Spherical racemes on stems growing in axils of stem leaves.
Flowers: On short stems ; 5 sepals, green with narrow pointed tips ; 5 petals forming standard, 2 wings and keel, yellow, up to 3.5mm long and dropping off after flowering ; 10 stamens, the top filament being free ; superior ovary.
Fruits: Kidney or sickle-shaped.
Annuals or short-lived perennials, flowering from May to September. – See more at: http://www.from-ireland.net/history/The-Real-Irish-Shamrock%3A-Imagery#display