Hammarbya paludosa (or Malaxis paludosa) is a small orchid commonly known as bog orchid, bog adder's-mouth or bog adder's-mouth orchid. It grows in bogs in temperate and subarctic regions of the Northern Hemisphere.
It was originally named Ophrys paludosa by Carl Linnaeus. The name paludosa refers to the boggy ground where it grows. In 1891, Otto Kuntze moved it to a new genus of its own called Hammarbya, named after Hammarby, Linnaeus’s summer residence.[1] Alternatively it is placed in the genus Malaxis.[2]
It is a small, inconspicuous orchid which can reach 15 cm in height but usually grows to between 4 and 8 cm. The stem is yellow-green, has three to five corners and grows from a small pseudobulb wrapped in two to five reduced leaves.[3] There are two, three or sometimes four basal leaves. These are oval to oblong, fleshy and pale green or yellow-green. The edges and tips curve inwards. There are one to three small, scale-like leaves higher up the stem. The leaves may have small bulblet-like reproductive structures on their margins.[3]
The flowers grow in a spike-like raceme that is 1.5–6 cm long and bears up to 25 flowers. They are small and greenish, about 2 mm wide and 4 mm tall. They have three sepals and three petals, one of which is modified to form a lip. There is one dorsal sepal pointing downwards and two lateral sepals pointing up. The two normal petals are small, narrow and strap-shaped and curve back around the sepals. The short, triangular lip is dark green with paler stripes and points upwards and forwards. The flowers have a sweet, cucumber-like scent.
In the majority of orchids, the flowers are resupinate, twisting 180° during development so that the lip points downwards. In Hammarbya paludosa, the flowers twist a further 180° so that the lip once more points upwards. Charles Darwin noted this feature in his 1862 book Fertilisation of Orchids.[4]
Hammarbya paludosa has a wide range around the Northern Hemisphere. In Europe it occurs north to 69° in Scandinavia and south to the Italian Alps, Balkans and Romania. It occurs locally across southern Siberia east to Sakhalin and Japan. In North America, it is found from Alaska east to Ontario and south to Minnesota.[5] (Codes) [6] In the British Isles it is found widely but very locally with the largest numbers in north-west Scotland. It has disappeared from much of England but is more frequent in the New Forest.