Field of Science

Borage and Comfrey and Bugloss


Anchusa undulata ssp. granatensis. Photo by James Gaither.


The tribe Boragineae includes about 170 species of herbaceous flowering plants, mostly found in the Palaearctic region with only a couple of species extending into southern Africa. The group is well-distinguished by the presence of what are called fornices, the whitish lobes at the base of each petal that you can see in the photo above, as well as features of their seeds. Many Boragineae seeds have an elaiosome, a fatty plug at one end that attracts foraging ants (Hilger et al., 2004). The ants carry the seed back to their nest as food, but the plant produces enough seeds that at least some will not be eaten but will be able to germinate after being carried under the ground and away from anything else that might eat them.


Abraham-Isaac-Jacob, Trachystemon orientalis, a native of forests around the Black Sea and one of the more unusual species of Boragineae. Apparently the unusual name refers to the flowers changing colour as they age. Photo by Daniel Mosquin.


The species are divided between about fifteen genera (the exact number varies depending on whom you ask). The largest generally-recognised genus, Anchusa (the buglosses), was identified by Hilger et al. (2004) as para-/polyphyletic with a number of smaller genera also nested within the Anchusa clade, suggesting that the currently recognised constituent subgenera may need to be recognised as separate subgenera (or else the genera Lycopsis and Cynoglottis submerged into Anchusa). Other relationships within the tribe recognised by this and other studies include a close relationship between the genera Borago (borage) and Symphytum (comfrey), and between Nonea and Pulmonaria (lungwort). The basalmost member of the tribe is Pentaglottis sempervirens, which is also the only member of the tribe found in the Atlantic region of southwest Europe. The relict distribution of this species, as well as the concentration of diversity for the tribe overall, have been cited as supporting a Mediterranean origin for the Boragineae.


Green alkanet, Pentaglottis sempervirens, the sister species to all other Boragineae. Photo by Carl Farmer.


A number of members of the tribe have long been cultivated and many are even labelled by their botanical names as officinal (the Medieval Latin term 'officinalis' refers to a plant or substance that is kept in an apothecary; not surprisingly, many plants with supposed medicinal values are also eaten for their nutritional values). Borago officinalis, borage, is used as a salad or pot herb in Europe. Symphytum officinale, comfrey, has also been widely used medicinally, mainly for external uses such as soothing bruises (some of the properties attributed to comfrey verge on the ridiculous: a bath steeped in comfrey was supposedly able to restore a woman's virginity). Pulmonaria officinalis, lungwort, received its name because of the supposed resemblance of its blotchy leaves to lung tissue. Under the unabashedly loopy herbalist principle known as the Doctrine of Signatures, this outward resemblance indicated its suitability in treating lung diseases such as tuberculosis (in fact, lungwort contains toxic alkaloids that make it dangerous to take internally).

REFERENCES

Hilger, H. H., F. Selvi, A. Papini & M. Bigazzi. 2004. Molecular systematics of Boraginaceae tribe Boragineae based on ITS1 and trnL sequences, with special reference to Anchusa s.l. Annals of Botany 94 (2): 201-212.

5 comments:

  1. Borage is also a source of commercial oils used mainly in health supplements (similar to Evening Primrose oil) and topical creams etc, as it is the best natural source of gamma-linolenic acid (with reputed, and disputed health benefits). Bizarrely, if you go to an oil-seed crushing plant which produces borage oil (there are one or two in the UK), the borage seed gives off a strong odour of mouse pee...

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  2. I thought it would probably be Iberian. I found five species of Echium in one small abandoned sea fort near Cadiz on my first visit to Spain. I wasn't going to guess this one without a flora. Damn the bastard who stole my Polunin.

    The most interesting species is not in the Boragineae any more. Alkanna tinctoria was banned from medicinal use by the Spanish Inquisition. Partly because it was supposed to be magical as its red root could change water into blood. Its modern name is "Raiz del Traidor", "root of the traitor" or "Raiz del Diablo" "root of the devil". The same pigments, though sourced from Lithospermum erythrorhizon, are highly valued in Japan as medicines.

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  3. "Some of the properties attributed to comfrey verge on the ridiculous: a bath steeped in comfrey was supposedly able to restore a woman's virginity."

    That really is virgin' on the ridiculous.

    [Apologies.]

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  4. the borage seed gives off a strong odour of mouse pee...

    "It's just borage seed that you can smell. Honest!"

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  5. Very nice post!
    I have just a comment. You wrote "The basalmost member of the tribe is Pentaglottis sempervirens, which is also the only member of the tribe found in the Atlantic region of southwest Europe."
    As a matter of fact, there are other representatives of the tribe in Atlantic SW Europe, as several Anchusa or Pulmonaria. Pulmonaria longifolia is very similar to Pentaglottis in range (although the former reaches Britain).

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