Prunella

Mr. Prunella; a parson: parson's gowns being frequently made of prunella.

The Prunella, or Self-Heal.

Fig. 48.—"Rejoicing in the shade of over-arching elms."

In your summer-walks, dear reader,—summer-walks through green lanes rejoicing in the shade of over-arching elms, or along woodland glades, carpeted with odorous turf,—you must frequently have met with an herbaceous plant, whose purple-blue flowers, arranged in regular succession, form the prettiest coloured cones imaginable at the extremity of the stem and branches. To this plant, the self-heal, we shall return immediately. Perhaps you have passed it by somewhat indifferently, for we pay little heed to common things, and on the threshold of woods, and in their winding avenues, the self-heal is very common. The celebrated German botanist, Bock (or Tragus) bestowed upon it, two centuries before the epoch of Linnæus, the name of Prunella vulgaris. The specific appellation, vulgaris, is here employed very appropriately, but we should commit a grave error if we supposed every species qualified as vulgaris  to be "common." For example, the Lysimachia vulgaris, a species of Primulaceæ, is far from being found everywhere.

Fig. 49.—The Prunella.

Pray, take the trouble to pick one lowly specimen; being specially careful to take up the whole plant, stem, root, and branch. Lying along the ground, it seems larger than it really is. Its root is a creeper; at the level of the insection of the leaves some small shoots project, the fibrous radicles which compel the lower part of the stem to crawl like the bugle, Ajuga reptans.

Does the prunella belong to the family of Labiatæ, like the bugle?

See for yourself. The stem is quadrangular; the branches and leaves composed of two lips. The stamens are four in number, two of which are longer than the others; finally, by means of a lens, you can easily distinguish, at the very bottom of the calyx, four tiny seeds (a tetrachænium ) grouped around the style. These features indicate that our plant belongs, in effect, like the bugle, to the Labiatæ family.

But mark the difference. In the bugle, as in all the species of the same genus (Ajuga ), as well as in all the Teucriums —of which wild sage (Teucrium scorodonia ) is the most widely-diffused type—in all the Labiatæ, the corolla is apparently unilabiate ,—that is to say, the upper lip is so shortened that only the lower is prominently visible. This is not the case with our self-heal: it is distinctly bilabiate. The upper lip of the corolla here forms a positive hood , sufficiently ample to protect the didynamous stamens (two long and two short), as in Fig. 50, a ; the lower lip is three-lobed, and the central lobe is largest of the three. By separating the two lips, you can see the two short stamens fixed to the base of the lower one, and the two long attached to the central part of the upper. (See Fig. 50, b.)

Let us pursue the analysis of the flowery cone you hold in your hand.

Fig. 50.—The Lips of the Prunella vulgaris.

The least practical eye is immediately struck by the arrangement of the parts and the variety of the colours. To recognise these things more thoroughly, please to cast your glances alternately from the top to the base, and from the base to the apex of its terminal flower. A little below the base you will see a pair of opposite, entire, and sinuous leaves, with shorter stalks than any of the others. The base is defined by two opposite, whitish, and nearly triangular leaves, with green points. The top of the floral spike is likewise marked by a couple of bracts; but these are much smaller, and red-coloured, like the two leaves of the calyx. The interval is occupied by bracts, which diminish in size from the base to the top of the spike; on a level with each pair six flowers are inserted, three for each bract.

The flowers, thus arranged by whorls, present some interesting peculiarities. The lower and upper show only their reddish calices; the middle, for the most part, display both a calyx and a corolla, varying from blue to pale-rose, which gives the plant a very peculiar appearance. In the under flowers, the corolla has already fallen; by separating the lips of the calyx, you may catch sight of the tetrachænium, that is, the four-seeded fruit, which is developed at the bottom of the tube. In the upper flowers, the corolla is not yet expanded. It resembles a small deep-coloured globe; you may say an eye, a bull's-eye, which, from the depths of the calyx, regards you with a piercing glance. Hence, perhaps, the French name for this plant, prunelle , an eye.

We often meet with a variety of self-heal with a white corolla, green calyx, and pinnatifid leaves, a variety of which some botanists have erroneously made a separate species, under the name of Prunella alba. It is equally wrong, in our opinion, to convert the large-flowered variety into a distinct species, by taking as its specific character the lateral cleft of the upper lip of the calyx overlapping the middle cleft ; for this same characteristic is found in many individuals of the common species. The dentiform appendage  which the two longest stamens exhibit at the top of their filaments is also an uncertain feature; you must have recourse to your magnifying-glass to see if this appendage is obtuse  and very short, as in the large-flowered prunella, or sharp , as in the common species. As for the size of the corolla, it is, in fact, very marked; but, as a characteristic, is wholly insufficient. The creation of the varieties Pinnatifida Laciniifolia , and Integrifolia  is no better justified. For it is no rare thing to see on the same stalk, at different heights, pinnatifid, whole, and laciniate leaves.

The prunella is remarkable for the long hairs which garnish the calyx, and, principally, the edges of the bracts. Examined in the microscope, they assume the form of tiny, pointed bamboos; the knots bulge out a little, and the intervals are punctuated.

The botanists of the sixteenth and seventeenth centuries are by no means sparing in their eulogiums on the marvellous virtues of our flower, which, by the way, Bock (Tragus) was the first to figure with tolerable accuracy.[62]

Tournefort thus dwells upon its medicinal properties:—

"It forms an ingredient in arquebusade water and vulnerary potions. It is ordered in possets and broths, in apozèmes for the spitting of blood, dysentery, hæmorrhages, and the like. It has also been used for ulcers in the mouth, and a remedy against headaches; after being mixed with rose-oil and vinegar, the temples were bathed with it."

In the Pharmacopœia of to-day, however, it finds no place.


[62]Tragus, "Historia Stirpium," p. 310 (ed. 1552).