This was interesting. I like when plant lore connects to the Gods and Goddesses.
Her hair was thought to resemble the grains of ripened grain, but I wasn't thinking The Norse countries were very well known for being wheat producers.
The plant they talk about, spp. Polytrichum ( https://en.wikipedia.org/wiki/Polytrichum
) being Sif's hair, has several varieties
some with the common name bird wheat, or pigeon wheat so I wonder if that was a source of the wheat idea. I would imagine fields of this moss growing must look like golden locks of hair and herbs can take on many common names, sometimes all for the same plant.
There seems to be many different mythologies that had the God/King/Ruler, uniting with the earth or marrying the earth. It reminds me of the "as above, so below" saying that all things are reflective. It also shows the commitment these Gods had to the area in which they were associated.
Thanks for the link.