Variations on a Theme: Forget-me-not, Heartleaf or Green Alkanet?

Why is it that we like to identify plants? To check whether it is safe or to eat or not, perhaps, or as a first step in working out how to buy one. To check if it is generally regarded by tastemakers as a weed or as a fit plant for a garden. But there’s also a great satisfaction in being able to name a plant just because we can. We feel closer to things we can name.

In April and early May, walking through fields and woods and peeking into gardens, we’ll often see plants with tiny, blue flowers that lift our spirits. They can be solitary, but more often, they are spreading.

Their pure blue flowers are classic forget-me-not style, the simplest of flower shapes with a starry look. Tiny, open flowers about as big as our smallest fingernail contain five rounded petals around a yellow, orange or white centre. But is it a forget-me-not? Perhaps it is, perhaps not.

The three most likely candidates are all in the Boraginaceae family. Forget-me-nots are so charismatic and well loved, they spring to mind first, which means that many plants are misidentified.

Here’s a quick guide to narrow down the options:

• If the plants are ankle high, or just a little taller, with slender green leaves held here and there, and flowers held in little clusters, consider forget-me-not (Myosotis).
• If blue flowers are around knee height, held in airy sprays on wiry, leafless stems above a cluster of leaves, consider heartleaf (Brunnera).
• If blue flowers are held fairly tight against pointed leaves on a tallish, sturdy flower spike, consider Green alkanet (Pentaglottis).

And a bit more detail on each:

Myosotis sylvestris | Forget-me-not

Each plant produces several flowering stems that divide and carry little clusters of blue forget-me-not flowers all over the plant, held facing upwards,  as if tiny flower posies are being presented to us. It’s an airy effect, especially as the flowers age and go to seed.

The whole plant is dainty. The green leaves are slender, ovalish, with a smooth outline and a central vein, held singly here and there on the flowering stem. They are a little hairy.

Wild forget-me-nots tend to be blue in the UK, but you can also buy white ones and pretty pink ones. Pink flowers sometimes appear on a largely blue plant. The central eye may be orange, yellow or white or a mix. Look closely and you’ll see a raised star shape around the eye as if the flower has been embossed.

Common species include Myosotis sylvestris (wood forget-me-not, mostly in woodland edges, access roads and hedgerows), Myosotis arvensis (field forget-me-not), Myosotis alpestris (alpine forget-me-not).

Brunnera macrophylla | Heartleaf

Other names include Siberian bugloss and, confusingly, Great forget-me-not.

The flowers are just as small, held in airy sprays well above the leaves. They are generally blue with a white eye, although Brunnera macrophylla ‘Betty Bowring’ is a pure white form.

Brunneras’ leaves are often beautifully marked with silver, golden yellow, cream or white although they can be plain green. Large, heart shaped leaves cover the ground at the base of the plant. Leaves on the flowering stems have a classic, pointed leaf shape.

While Brunnera tolerates dry shade, it performs best with more water-retentive soil.

Pentaglottis sempervirens | Green alkanet

Green alkanet is much sturdier and taller than Myosotis and is thickly covered in pointed, hairy, veined leaves that are larger towards the bottom of the flowering stem. Flowers are produced at different heights on leafy, tapering towers and are held close to the leaves singly, and in small clusters.

The flowers are a very pure, gentian-like blue with slightly raised, white eyes. Each petal overlaps its neighbour. The buds have hints of pink or purple and some flowers have a purplish star shape around the centre, especially when they first open.

Green alkanet flowers over a relatively long period, particularly if cut back after the first flush. It is happy in dampish shade and can be hard to eradicate. Pollinators help it set seed readily. The tap roots in an established clump run deep and are brittle so tend to snap off when land is cleared, then spring back into life.

Other options

If you can rule the three most likely options out, other possibilities include Omphalodes, which can be pure blue, although my favourite is Omphalodes cappadocica ‘Starry Eyes’.

Apparently Borago (Borage), Symphytum (Comfrey) and Pulmonaria (Lungwort) are often confused with forget-me-not too, although their flowers are not all that similar.

Borage has nodding flowers with a prominent beak-like centre and green sepals that form a star shape on the back. The petals are pointed and often twisted, not rounded. Hairy buds are held in clusters.

Comfrey flowers are tube shaped, held in drooping clusters. Their colours are alluring, often with blue, white and pink on the same plant.

Pulmonaria has flowers that do look like a forget-me-not from the front, but from the side, they extend into a tiny horn shape and have green or dark leafy holders. The leaves are often spotted silver or white. Blue varieties such as ‘Blue Ensign’ are the most likely to be misidentified as forget-me-not.

Finally are they weeds? Each person reading this will have their own idea of that, which is quite as it should be. But one of the most beautiful spring flower borders I’ve ever seen had an underplanting of forget-me-nots in some places and green alkanet in others.