RECENTLY, in a publication
named "The Quiver," the Rev. Dr. Hugh Macmillan, who, as will be already
inferred, has given considerable study to the Heather plant, wrote as
follows on the parasitical nature, or what scientists term "symbiosis,"
of the Calluna.
He says:
"In the bright autumn days the Scottish moorlands are covered from end
to end with crimson Heather in full bloom. The Heather is one of the
hardiest of plants, and is so well adapted to its growing place that we
cannot imagine the moorlands without it. It looks as if it belonged to
the bleak, mist-drenched soil, and grew out of it of its own accord. We
naturally suppose that each Heather bush of the myriads upon which we
gaze supports itself by means of its own roots, taking out of the brown
peat by its own vital powers, in the exercise of its own special
functions, the nourishment which it needs. Of all plants, the Heather,
we should suppose, would be the most independent and self-sustaining,
growing as it does so luxuriantly in such desolate situations. But
science tells us that this is not the case. The Heather is rooted, not
in the dead peat, but in the living mycelial material in which its
rootlets are wrapped up. It cannot nourish itself, but must be nourished
by a foster-parent, so to speak, which prepares its food for it, and
reduces the peat on which it grows to a condition which it is able to
absorb and circulate as food throughout its system. If you dig up
carefully a Heather bush by the roots, and examine the finer fibers at
the end of these roots, you will find that they are covered with a thin,
whitish mantle or cobweb of delicate threads. This is not a part of the
roots; it does not belong to the Heather at all. It is a separate living
plant growing on the Heather roots—the spawn of a minute fungus. It is
found upon every Heather bush, and spreads from root to root, causing
all the wide acres of bright moorland vegetation to flourish from year
to year by its living action. The connection between these two organisms
is not only of the closest character; it is also lifelong. When once the
partnership is formed it continues uninterruptedly as long as they both
exist. As the roots grow and spread, the spawn of the fungus grows and
spreads with them. Were this living fungous growth to be taken away from
the roots of the Heather, the bush, even if supplied with every other
requisite, growing in its own proper soil, and furnished with its own
suitable food, would soon wither and die. The true secret of the failure
which so often attends the transplanting of Heather is, that in the
process this fungous growth is torn away from the roots, and it takes
some time to form a new growth of it in the new soil, while in the
meantime the Heather, bereft of its accustomed partner, languishes and
dies. The first Scottish emigrants to Canada took with them some Heather
bushes to plant in the new country in order to remind them of the dear
old Highland home. But they did not know that they had broken off the
strange association of the Heather plants with their fungoid friends in
their native peat mould, and therefore the experiment necessarily proved
abortive, and the poor Highlanders had to weep over the sad failure,
naturally attributing it to a sentimental cause."
I submitted the reverend gentleman's statement to
the late Professor Thomas Meehan, of Germantown, Pa., who kindly made
the following comment thereon:
"The Rev. Hugh Macmillan states that the roots of
a fungus prepares food for the Heather, and that the Heather roots
furnish dead material as food for the fungus. I am asked whether this
view is sound. It has been found that many plants do live in
companionship in this way, and the term symbiosis has been coined to
represent the phenomena. But I have not heard that the Heather is one of
this class. The article, on the whole, is written very intelligently,
and seems to have been founded upon well-recorded facts. On my grounds
the Heather thrives as in its native wilds, but I have never suspected
it of this habit. When the frosts of winter have passed I shall have
pleasure in examining the roots."
(Both of these articles appeared in "The Florists'
Exchange," a trade paper published in New York City.)
Subsequently Professor Meehan furnished other
particulars concerning this matter, as follows:
"The foreman in charge of the department having
oversight of these matters in the nursery of Thomas Meehan & Sons places
the following note on my table. I have no doubt but that the doctrine of
symbiosis, sound in sonic degree, is, like many other scientific
discoveries, pushed to the verge of absurdity. I have little idea that
it has a place in the economy of the Heather; but as we have it growing
as if at home, I have given the writer the benefit of that little, by
deciding to examine the roots for myself in the growing season.
"'Dear Sir: After reading your communication to
"The Florists' Exchange," regarding symbiosis of the Heather, I thought,
perhaps, you would like me to call your attention to the fact that, in
your lower greenhouses, there is a batch of C. vulgaris cuttings that
were put in last October in pure sand. Over 90 per cent. have struck and
are growing.
"'The Rev.
Hugh Macmillan's fungus is evidently not necessary to the Heather in the
young state, or else it is a constitutional matter without which the
Heather would not be in existence."'
The lamented death of the eminent gentleman
unfortunately precluded further light being thrown on this most
interesting phase of Heather Lore.
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