The Chiltern wood borders are the place to look for the Military Orchid,
Orchis militaris. At one time this was not extremely rare, and up
to about a century ago there are records of it being seen in considerable
numbers. Moreover, the records extend from east of Tring across the
Thames into Berkshire; and they were from places well scattered over the
Chilterns (Distribution Map, p.222). Then it disappeared from one district
after another, until by about 1914 it seemed to be extinct. Whatever the
reason for its going - and there are quite a number of theories - there
must have been some factor which affected it over a wide area. In May,
1947, I rediscovered the Military Orchid! In a way it was just luck. The
excursion was intended as a picnic, so I had left my usual apparatus at
homc and took only my note-book. But I selected our stopping places on
the chalk with some care, and naturally wandered off to see what I could
find. To my delight I stumbled on the orchid just coming into flower. The
following week-end I returned to make a careful survey of the colony and
to take the first opportunity given to any British botanist for well over
thirty years of studying the particular conditions under which the Military
Orchid lives in our country. It was on this second visit that I took the
colour photograph used for Plate 26 (p.115) - the first to be taken of
this plant in England.
Careful plotting showed that there were 39 plants in the colony and
that 18 of them had thrown up flowering spikes. Of these, the 5 most exposed
had the flower-stems bitten right off - almost certainly by rabbits. The
plotting also revealed that the plants most in shade either failed to flower
or put up only pale, small spikes. Trees on one side of the colony had
been cut down in the early days of the war, as I estimated from the growth
of bushes round their stumps, and it is likely that this had stimulated
germination of dormant seeds of the orchid. Analysis of a sample of the
soil revealed that the free carbonate of lime amounted to no less than
50.2 per cent-an astonishingly high proportion.
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It was interesting to compare this locality with the marshes near Brunnen
in Switzerland, where I saw the Military Orchid in May, 1930. Whereas on
the Chilterns it was growing on a shallow chalk soil under almost the driest
possible conditions, in Switzerland it thrived in very wet marshy meadows.
It is probable, however, that the soil-water there was basic, although
I made no tests at the time.
The plants on the Chilterns varied greatly in size. The smallest was
only about four inches tall with two flowers - a miserable, depauperate
little plant. The largest - the one which is illustrated - was 14
inches (35 cm.) tall with no less than 26 flowers. This must be about the
finest Military Orchid seen in England; for most of the herbarium specimens
(dating from the time when it was plentiful) are only some 7 to 9 inches
in height.
The flowers are extremely beautiful; in saying this I think I can fairly
say that I have not allowed the rarity of the plant to bias my judgment.
The pointed sepals are folded together to form a hood over each flower
and are a pale ashy-grey on the outside. The flowers open at the bottom
of the spike first and therefore the buds at the top appear slightly pinkish-grey
from the colour of the sepals, which act as wrappers. It is the resemblance
of the hood to an ancient helmet which has led to the plant being called
the Soldier or Military Orchid; the name is a very apt one. The lip, which
projects beneath the helmet, has two lobes on each side and one very small
pointed terminal one: it is spotted and flushed with a colour which is
usually described as pink but which is far less red than is shown in most
of the published colour pictures. It is a colour which is very difficult
to match, but perhaps comes nearest to the one described as "roseine purple"
of the old R.H.S. colour chart. In 1955 a second fine colony of the Military
Orchid was discovered in Suffolk - far from previously known habitats. |