In this bleak November weather, I enjoyed seeing a few things in bloom recently, including borage and green alkanet. I wanted to further compare the two as they can be so similar. The bees love both. I'm not sure the temperature range of each but I do know that green alkanet is often one of the first flowers in Spring providing food for bees and it dies back in time for other flowers to take over.
Borage
Green Alknaet
Leaves
both hairy, slightly stinging, textured
borage (left) is rounded at the end, green alkanet (right) lanceolate pointed at the end and sometimes has blisters
sometimes the borage leaves are more lanceolate
Stems
borage leaves grow from the (often thick) stem
green alkanet (on the right) leaves growing on stems from the base, at least initially
older green alkanet with flowering stems
Flowers
borage, tight clusters of flowers (see buds to the left above), green alkanet sparser flowers (see below)
Prevalence of Borage and Green Alkanet
Green alkanet self-seeds widely and takes a while to get established before blooming. Borage self-seeds quite closely and takes less time to flower. So my garden is full of green alkanet small plants but not many borage. Top left, below, green alkanet small plants; bottom right below borage.
Similar Leaves
Foxglove has a tight rosette initially. The leaves are very textured but very soft unlike the borage and green alkanet.
Honesty (Lunaria annua) has heart-shaped similarly textured leaves, green alkanet (with blishters on the leaves to the right)