Golden (aka Tall) Melilot is easily confused with : Ribbed (aka Common) Melilot.
Various sources claim:
- That contrarily to the name, Ribbed (aka Common) Melilot is slightly taller than Golden (aka Tall) Melilot and yet, equally perversely, they both grow to 1.5m.
- That Ribbed Melilot has lemony yellow flowers whereas Golden Melilot has golden yellow flowers.
- That Ribbed Melilot has the keel shorter than the standard and wings, whereas the two are equal length in the case of Golden Melilot.
- That Ribbed Melilot is less compact and with lighter coloured stems than Golden Melilot.
- That Ribbed Melilot has a less dense flower spike than does Golden Melilot.
- And finally that the only way to tell them apart is by whether the pods are black and hairy (in the case of Golden Melilot) or hairless and olive-green in the case of Ribbed Melilot!
Strikingly, no sources claim that Ribbed Melilot is ribbed; all Melilots seem to be (in places) ribbed! It is obvious from the names alone that confusion has reigned supreme here.
Given such confusion, there is no guarantee that your author has correctly differentiated between the two commoner yellow Melilots in the photos shown here.
Uniquely identifiable characteristics: there is no mistaking that it is a Melilot. But which one...
The BSBI distribution map of both suggest that it can only be
Tall Melilot, since Ribbed Melilot has not been seen on Walney Island since the new century began in 2000 AD.
But it is definitely not:
Furrowed Melilot (Melilotus sulcatus) which hasn't been seen in the UK since the 1990's nor is it
Round-fruited Melilot (Melilotus infestus) which hasn't been seen in the UK for even longer.
The only reliable method of differentiating between Golden Melilot and the otherwise very similar Ribbed Melilot (Melilotus officinalis) is the size, colour and pattern of lumps of the fruits. The fruits of Tall Melilot (aka Golden Melilot) are 5-7mm long, black when ripe and either reticulated or transversely-ridged. Whereas those of Ribbed Melilot are shorter at only 3-5mm long, brown when ripe and just transversely ridged, but the ridges are not continuous, but rather in 3 rows. Gather a few to examine and measure.