By J. CH. SAWER, F.L.S.
Lavender--technically _Lavandula_. This name is generally considered to
be derived from the word _lavando_, gerund of the verb _lavare_, "to
wash" or "to bathe," and to originate from the ancient Roman custom of
perfuming baths with the flowers of this plant.
The general aspect of the various species which compose this genus of
labiate plants, although presenting very characteristic differences,
merges gradually from one species to another; all are, in their native
habitat, small ligneous undershrubs of from one to two feet in height,
with a thin bark, which detaches itself in scales; the leaves are
linear, persistent, and covered with numerous hairs, which give the
plant a hoary appearance.
The flowers, which are produced on the young shoots, approximate into
terminal simple spikes, which are, in vigorous young plants, branched at
the base and usually naked under the spikes.
As a rule, lavender is a native of the countries bordering on the great
basin of the Mediterranean--at least eight out of twelve species are
there found to be indigenous on mountain slopes.
The most commonly known species are _L. vera, L. spica_ and _L stæchas_.
Commercially the _L. vera_ is the most valuable by reason of the
superior delicacy of its perfume; it is found on the sterile hills and
stony declivities at the foot of the Alps of Provence, the lower Alps of
Dauphiné and Cevannes (growing in some places at an altitude of 4,500
feet above the sea level), also northward, in exposed situations, as far
as Monton, near Lyons, but not beyond the 46th degree of latitude; in
Piedmont as far as Tarantaise, and in Switzerland, in Lower Vallais,
near Nyon, in the canton of Vaud, and at Vuilly. It has been gathered
between Nice and Cosni, in the neighborhood of Limoné, on the elevated
slopes of the mountains of western Liguria, and in Etruria on hills near
the sea. The _L. spica_, which is the only species besides _L. vera_
hardy in this country, was formerly considered only a variety of _L.
vera_; it is distinguished by its lower habit, much whiter color, the
leaves more congested at the base of the branches, the spikes denser and
shorter, the floral leaves lanceolate or linear, and the presence of
linear and subulate bractes.
It yields by distillation an oil termed "oil of spike," or, to
distinguish it from oil of _L. stæchas_, "true oil of spike." It is
darker in color than the oil of _L. vera_, and much less grateful in
odor, reminding one of turpentine and rancid coker nut oil. It is used
by painters on porcelain, and in the manufacture of varnishes. It is
often largely admixed with essence of turpentine.
_L. Stæchas_ (Stichas) was discovered prior to the year 50 A.D. in the
Stæchades Islands (now the Islands of Hyères), hence the name. At
present it is found wild in the South of Europe and North of Africa,
also at Teneriffe. The leaves are oblong linear, about half an inch long
(sometimes an inch long when cultivated), with revolute edges and
clothed with hoary tomentum on both surfaces; the spike is tetragonal,
compact, with a tuft of purple leaves at the top; the calyces are ovate
and slightly shorter than the tube of the corolla. The whole plant has a
strong aromatic and agreeable flavor. There is a variety of this species
(_L. macrostàchya_) native of Corsica, Sicily, and Naples, which has
broader leaves and thicker octagonal spikes.
_L. stæchas_ is known in Spain as "Romero Santo" (sacred rosemary). Its
essential oil (also that of _L. dentata_) is there obtained for
household use by suspending the fresh flowering stalks, flowers
downward, in closed bottles and exposing them for some time in the sun's
rays; a mixture of water and essential oil collects at the bottom, which
is used as a hæmostatic and for cleansing wounds.
The specific gravity of Spanish oil of _L. stæchas_ is 0.942 at 15° C.
It boils between 180° and 245°. The odor of this oil is not at all
suggestive of that of lavender, but resembles more that of oil of
rosemary, possessing also the camphoraceous odor of that oil. In India
this oil is much prized as an expectorant and antispasmodic.
[Illustration: LAVANDULA VERA. LAVANDULA SPICA.
(From photographs of the plants. Natural size.)]
The other species which are distinctly characterized are _L.
pedunculata, L. viridis, L. dentata, L. heterophylla, L. pyrenaica, L.
pinnata, L. coronopifolia, L. abrotonoides, L. Lawii_, and _L.
multifida_.
The _L. multifida_ is synonymous with _L. Burmanii_. In Spain the
therapeutic properties of _L. dentata_ are alleged to be even more
marked than in the oils of any of the other species of lavender. It is
said to promote the healing of sluggish wounds, and when used in the
form of inhalation to have given good results in cases of severe
catarrh, and even in cases of diphtheria. In odor this oil strongly
suggests rosemary and camphor. Its specific gravity is 0.926 at 15° C.
It distills almost completely between 170° and 200°.
The specific gravity of the oil of _L. vera_ (according to Flückiger and
Hanbury, _Pharmacographia_) ranges between 0.87 and 0.94. The same
authorities state that in a tube of 50 millimeters the plane of
polarization is diverted 4.2° to the left.
Dr. Gladstone found (_Jnl. Ch. Soc._, xviii., 3) that a sample of pure
oil of _L. vera_, obtained from Dr. S. Piesse, indicated a specific
gravity of 0.8903 at 15° C., and that its power of rotating the plane of
polarization (observed with a tube ten inches long) was -20°. Compared
with these results he found the sp. gr. of oil of turpentine to be
0.8727, and the rotatory power -79°.
Although _L. stæchas_ was well known to the ancients, no allusion
unquestionably referring to _L. vera_ has been found in the writings of
classical authors, the earliest mention of this latter plant being in
the twelfth century, by the Abbess Hildegard, who lived near
Bergen-on-the-Rhine. Under the name of _Llafant_ or _Llafantly_, it was
known to the Welsh physicians as a medicinal plant in the thirteenth
century. The best variety of _L. vera_--and there are several, although
unnamed--improved by cultivation in England, presents the appearance of
an evergreen undershrub of about two feet in height, with grayish green
linear leaves, rolled under at the edges, when young; the branches are
erect and give a bushy appearance to the plant; the flowers are borne on
a terminal spike, at the summit of along naked stalk, the spike being
composed of six to ten verticillasters, more widely separated toward the
base of the spike; in young plants two or four sub-spikes will branch
alternately in pairs from the main stalk; this indicates great vigor in
the plant, and occurs rarely after the second year of the plant's
growth. The floral leaves are rhomboidal, acuminate, and membraneous,
the upper ones being shorter than the calyces, bracteas obovate; the
calyces are bluish, nearly cylindrical, contracted toward the mouth, and
ribbed with many veins. The corolla is of a pale bluish violet, of a
deeper tint on the inner surface than the outer, tubular, two-lipped,
the upper lip with two and the lower with three lobes. Both the corolla
and calyx are covered with stellate hairs, among which are embedded
shining oil glands, to which the fragrance of the plant is due. The _L.
vera_ was identified in 1541, and introduced into England in 1568,
flourishing remarkably well under cultivation, and yielding an oil far
superior in delicacy of fragrance to that obtained from the wild plant,
or to that obtained from the same plant cultivated in any other country.
When it is remembered that north of the 50th degree of latitude the vine
yields little but garlands of leaves, and that we should attempt in vain
to cultivate the olive north of the 44th degree, it may seem strange
that the _Lavandula vera_, which is a native of about the same climate
as these, should resist, unprotected, the vigorous frosts of this
country. Even at Upsala, latitude 59° 51' N., in the Botanic Garden, it
merely requires the shelter of a few branches to protect it in the
winter; but this hardiness may be accounted for by several physiological
reasons. Like all fruticulose labiates which have a hard compact tissue
and contain much oily matter, the lavender absorbs less moisture than
herbs which are soft and spongy, and, as it always prefers a dry
calcareous, even stony, soil, the northern cultivators find that by
selecting such localities the tissues of the plant take up so little
water that the frost does not injure them.
In a northern climate the length of the days in summer, and the natural
dryness of the air, compensate in some measure the reduction of
temperature, and mature the plant only to the extent sufficient for the
purpose for which it is grown. Perhaps the suspension of vital action
during winter, which must be more complete in northern latitudes, as our
frosts are more severe, tends to preserve certain plants, native of the
south, for it is observed that all plants are more sensitive to cold
when vegetation is active than when it is at rest. The vine is an
instance of this. On the other hand, when the plant is cultivated
further south than its natural boundary, the same causes seem to exert
their influence, but in the reverse sense. Lavender is cultivated on the
mountains of Yemen, in Arabia; the humidity, increasing inversely to the
latitude, compensates the exhaling force of the sun's rays, and the
elevation of the locality the effects of the heat.
Thus is confirmed, both in north and south, the law of vegetable
physiology observed by De Candolle, in the temperate climates of France,
and published in his "Essai de Geographie Botanique," that "plants can
best resist the effects of cold in a dry atmosphere, and the effects of
heat in a humid atmosphere." A mild, damp winter, like the one of
1889-1890, does more harm than a hard, seasonable frost, as the plants
are apt to make green shoots prematurely, and the late frosts nip off
these tender portions, each of which would otherwise have produced a
flower spike.
The very severe winter of 1890-1891 did not kill so many plants as the
one of 1889-1890. The stems and branches of lavender being ligneous and
strong are able to resist the force of the wind, and the plant thrives
best in a perfectly open locality, where the air circulates freely; the
oil and resin which it contains in abundance enable it to resist the
parching action of the wind and sun. Thus, on the most arid and sterile
ground on the mountain sides in the south, and especially in Spain,
plants of this genus flourish with more vigor in the season when most
other vegetation is scorched up by the ardent rays of the sun, and the
_Lavandula vera_ seems to have a predilection for such spots.
Certainly the plants then assume a more stunted appearance than in
richer soil, but at the same time the perfume is stronger and sweeter.
The calyces become charged with oil glands, and yield a greater
abundance of volatile oil.
In a very moist soil the water penetrates too much into the tissues,
detaches the bark, the plant blackens at the root, and a white fungus
attaches to the main stem and lower branches; it becomes feeble,
diseased, and dies. A rich soil furnishes too much nutriment, the plant
grows very large and herbaceous, becomes overcharged with water relative
to its assimilating and elaboratory power, especially if growing in a
cold climate, and the equilibrium of the chemical proportions necessary
for the formation of natural juices becomes deranged at the expense of
quantity and quality of the volatile oil produced.
These facts, long ago pointed out by Linnæus, have been verified in
England. Some years ago a disease manifested itself in most of the
plantations, which, not being understood by the growers, was not
remedied (in fact, is not generally understood and remedied at the
present time), the acreage under cultivation decreased, and, partly
owing to this and a scarcity occasioned by a failure in the crop, the
price of the oil rapidly rose from 50s. to 200s. per lb. Consequently,
with the continually increasing demand and the continued rise in price,
manufacturers of lavender water and of compound perfumes in which oil of
lavender is a necessary ingredient commenced to buy the French oil, and
venders of the English oil commenced to adulterate largely the English
with the French oil.
By degrees the French oil become almost entirely substituted in England
for the English, and at present it is difficult to purchase true English
lavender water of a quality equal to that vended twenty years ago,
except at a few first class houses.
The exorbitant profits demanded by chemists and druggists, and the
incomprehensible will of the public to buy anything _cheap_, however
bad, have encouraged a marvelous increase in the figures of the imports
of French (and German, which is worse) oil.
In 1880, when the price had reached 125s. per lb., it was pointed out by
an eminent London firm that unless the cultivation in England were
extended, the price would become prohibitive, inferior oils would be
introduced into the market, and so destroy the popularity of this
beautiful perfume.
The price still rising did, in fact, induce this importation, and to
this day the bulk of chemists and perfumers continue to use these
foreign oils, notwithstanding the fall in the price of the English oil.
The constant demand, however, in America (where people will have things
good) will yet support the price of the genuine article--that is, of the
English oil, which is the finest the world produces. Attempts were made
by a French manufacturing perfumer to establish a plantation in the
south of France of plants taken from parent stems grown in England.
The result was that the young plants deteriorated to their original
condition--even there in their native habitat. The character of a plant
and the character of its produce depend even on more than a similarity
of soil and geographical position. It is asserted that a good judge can
distinguish between the oils produced by two adjacent fields, and the
difference in odor is very apparent between the oils produced in
Hertfordshire and in Surrey. The oil produced in Sussex is different
from both.--_Chemist and Druggist_.
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