Orchids

Waterside Natural History Society day with Orchids
Our original outdoor visit was cancelled to make way for a look at Orchids. It is always difficult to predict when flowers are at their best, particularly this year, so when we heard that the Orchids were coming into flower we quickly rearranged our schedule to take advantage of this opportunity.
Charles Darwin after he had written ‘The origin of the species’ followed up with ‘Fertilisation of Orchids by Insects’. This was no accident since besides being beautiful and elusive flowers they have a unique fertilisation adaptation. Insects normally fertilise flowers by picking up pollen from one flower and depositing it on another. This carries the risk however of self pollination but is avoided in the case of Orchids by a clever adaptation. The pollen lies in masses, pollinia, at the top of a stalk, caudicle, resting on a sticky base covered in a thin membrane, rostellum. When the insect touches the membrane it breaks exposing the sticky base which attaches itself and the pollinia to the proboscis of the insect. When it first attaches the pollinia is held vertically but after about half a minute it falls over to a horizontal position. This means that the insect can visit other flowers on the same stalk within the half minute without pollinating but when it later visits another orchid the pollinia is in the horizontal position which allows fertilisation.
If this seems complicated think of the many millions of gene formulations that must have occurred to enable this process to evolve and reach the perfection we see today. The individual orchid flower consists of three sepals and three petals but the sepals have been adapted to look like petals. Normally the three sepals are at the top of the flower and form a hood over the lower petals, two of which are in the form of wings to either side and the bottom petal is in the shape of a lip hanging down from the flower. A spur is usually positioned to the rear of the flower.
We had to travel to different locations in the New forest in order to see a variety of Orchids and we were lucky to have as a guide Roger Grieve who not only knew where they were but holds a vast amount of information about them. Sometimes we had to stop the car at the side of the road and dive in to a boggy area in order to inspect the orchids more closely.
The first four varieties of Orchid although not at the same location all belonged to the same group. This was the Dactylorhiza group which is characterised by having long bracts between the individual flowers of the flower spike. They can therefore be identified by their dense flower heads. The ‘Heath Spotted Orchid’ is usually identified as a pale pink rounded spike amongst the heather. They have a broad three lobed lower lip with the middle lobe the smallest. The dark markings on the individual flower tend to form a loop around the lower lip. However the size and shape of the middle lobe varies widely from one to another. The leaves are all very pointed running up the central stem and are pale green with circular purple spots on either side of the centre line.
The next orchid was the ‘Common Spotted Orchid’. It generally has a bigger and fuller flower spike with a Christmas tree look. The individual flowers have a lower lip with three almost equal lobes and the dark markings are more in the form of dots or blotches. The leaves are a darker green than the Heath Spotted with purple transversely elongated spots but the greatest difference is that the lower leaves are broad and elliptical. Orchid leaves are very tasty however and often the lower leaves are the first to be eaten.
The third orchid was the ‘Early Marsh Orchid which has particularly long bracts. A distinguishing feature is that the stem is hollow which can be observed by squeezing between the thumb and forefinger. The individual flower has a lower lip with sides that are bent back giving it a narrow look. Dark markings are U-shaped with blotches at the centre. The spur behind the flower is straight and tapering. Leaves which cling to the stem are all pointed; keeled, without spots, and rise to a hooded tip.
The fourth and last in the Dactylorhiza group was the ‘Common Marsh Orchid ‘which is sometimes divided into the northern and southern marsh orchids although only the southern is present in our area. The stem is stouter than the early marsh orchid so is not so obviously hollow. Flowers are usually dark rose purple and a good distinguishing feature is that the top of the stem below the flower head is also purple coloured. The lower lip is broad and does not bend back. Darker green leaves are broad, lanceolate and fan out from the stem.
Our next Orchid looked completely different from the previous four. It was the ‘Lesser Butterfly Orchid’ which has a slim open spike of pale yellow flowers. The bottom lip was in the form of a narrow tongue and at right angles to the back was a straight narrow spur. The sides of the hood had pink markings with a green top. The two pollinia stand vertical in the lesser butterfly orchid whereas in the greater they are curved as is the spur at the rear.
The sixth orchid was the ‘Marsh fragrant Orchid’ which even in the heat of the day had a powerful carnation like smell. The deep pink flowers appear to have a pea shaped centre with delicate horizontal wings but this is largely because of their small size and the lower lip being broader than it is long. The orchid has slim keeled leaves and bracts between the individual flowers but it still retains an open appearance.
We also saw one or two Bee Orchids but they were not yet in flower. A ‘Broad Leaved Helleborine’ and several ‘Marsh Helleborine’ were also seen but again not in flower. This brought our total for the day to nine different varieties; an impressive total for such a small area.