Melilotus species - Melilots

There is a good account of separating out Melliots by David Merrick here.

Melilotus albus White Melilot This is the only white-flowered member of the genus. The keel and wings are equal and the fruits 3 - 5 mm are brown when ripe and glabrous.

Melilotus officinalis Ribbed Melilot Standard and wings ±equal and keel shorter and fruits 3 - 5mm are brown when ripe and glabrous.

Melilotus altissimus Tall Melilot This is up to 1.5m tall like all the other species above. Standard, wings and keel ±equal and fruits 5- 7mm are black when ripe and hairy.