Once upon a time a Grape Hyacinth was a Grape Hyacinth and if you wanted to be scientific you called them Muscari. These days things are little bit more complicated.
Pseudomuscari were separated into a subgroup of Muscari in 1935, became a sub genus in 1965 and finally gained the status of genus in their own right in 1970.
A key characteristic, which sets them apart from their close Muscari relatives, is that the individual bell shaped flowers are not constricted at the mouth, but are instead, open.
The genus often have densely packed racemes of flowers which are most usually pale or bright blues.
As the flowers age from the bottom of the raceme, they take on deeper shades and loose the more obvious patterning.
I have purchased and germinated some seeds this year of Pseudomuscari azureum alba. I appreciate that even if I am lucky enough to get them to develop in to bulbs it is going to be a few years before I’m going to be able to photograph their flowers! I will be interested to see how the white ages.
Generally quite small plants, Pseudomuscari flower early in Spring. Since purchasing some bulbs in 2016, Pseudomuscari coeleste have been a reliable first flower in mid February, whatever the weather has thrown at them.
The plantlist.org lists seven accepted species of Pseudomuscari.