Husrygg Nature Reserve (on the Island of Gotland)
Visited June 9th, 2014 with the Lakeland Horticulture Society
Our first day on Gotland Island we would visit the southwestern tip of the island with scenic limestone bedrock and have mid-morning coffee and tea at a garden with a contemporary art sculpture park. Our lunch would be at a museum with a gallery of birds painted in their natural habitats.
Early Monday morning we left our summer cabin near the sandy Tofta beach on the island of Gotland and headed south along the western coast. Our initial scenery of the island were homesteads with agriculture land, horse and cattle farms, pastures for grazing sheep and wild orange poppies alongside the loosely stacked low stone walls that would follow the two lane road to the tip of the island. We reached the south of Gotland known as Sundre, where Carl Linnaeus had traveled through on horseback on July 9th, 1741. The landscape changed from forest of birch, oak and pine trees to short grassland and scrub bushes in chalky soil.
At the end of the narrow road on the southwest edge of the coast the landscape changed dramatically with towering soft limestone formations along the shoreline of the Husrygg Nature Reserve which follows to Gotland's Island southern rocky tip called Hoburgen. Carl Linnaeus observed the natural beauty he found there and a prominate limestone stack formation (later named Hoburgsgubben or"Old Man Hoburg") that he wrote of. "This Hoburg is one the most natural phenomena on all of Gotland. It is very lofty, formed like a most beautiful citadel…We marveled that such a remarkable spot, where Nature, who never makes anything without a purpose has created a masterpiece in such a strategic position at the southernmost tip of the island, without putting it to any use…" Linnaeus also wrote of the caves that penetrated the cliff face, the marble rocks that he found on the shore and the clifftops that teemed with butterflies.
Clumps of the bright blue prickly hairy plant,Viper's bugloss (Echium vulgare L.) dotted the rock strewn landscape at the Husrygg Nature Reserve. Native to southern Sweden, the Viper's bugloss blooms May to October. A soil too rich discourages flower formation which makes the bare coastal limestone habitat ideal for this drought hardy biennial herb whose roots extend deep in the ground several feet.
In the United States it is known by the common name blueweed. It may be an apt description since it is considered a noxious weed and all parts may cause mild stomach upset or other medical reactions if used in large quantities of herbal home remedies or teas. Bugloss means “ox tongue” in reference to the roughness of its leaves and contact with the foliage can irritate the skin. For grazing animals, especially sheep and horses, the Viper's bugloss can be poisonous if grazed heavily as it contains pryyolizidine alkaloids, which are found in the plants of the Boraginaceae family. Milk from dairy animals can be contaminated with the alkaloids. Alkaloids have also been found in honey collected from bees that forage on the toxic plants.
The clusters of the single stemmed Viper's bugloss (or in Swedish bläeld – blue fire),give no hint of its toxic potential at Husrygg, where the bright blue flowers contrast with worn dusky limestone and blends into the colbalt blue of the Baltic Sea.
In the limestone soil was also found a plant whose descriptive name would give pause as to any medicinal use of this herbaceous perennial herb with the Latin name Vincetoxicum hirundinaria Medik. Vincetoxicum comes from the Latin Vinco and toxicum, meaning “to overcome or subdue with poison.” The generic name Cynanchum (broken down into Greek) possibly refers to a past use of the plant as an animal poison. Linnaeus chose Asclepias (the Greek god of healing) for the name of the genus because of the many folk-medicinal uses for the milkweed plant. Modern taxonomy has moved Vincetoxicum hirundinaria (hirondo-Latin for swallow as it's seeds resemble a swallow wing or tail) from the Asclepiadaceae (milkweed) family to the Apocynaceae (Dogbane) family. The White swallow-wort, as its common name, has a life span of several decades. It is native to a large area of Europe (but not Great Britain) with the northwest limit of its distribution in Scandinavia on the islands and the stony limestone coastal areas of the Baltic Sea.
Swallow-wort may be descriptive of when the herbal plant was used medicinally in the treatment of tonsillitis. There can be poisonous effects though from the toxic alkaloids in the plant, including it poisonous fibrous roots. It is an invasive plant; it can not be grazed and with short branched rhizomes that spread, an individual plant has the potential to produce more than 100 flowering shoots.
According to current literature from studies in Finland, there are only three “specialized herbivores” that feed on the Vincetoxicum hirundinaria.
The Black-and-Red-bug (Lygaeus equestris L.) is a species of ground bugs that feed on plant juices, particularly the White swallow-wort and the Adonis vernalis or Spring pheasant's eye. This bug is protected from its potential predators since they store the toxic ingredients of the plant, making them an unappetizing meal.
Euphranta connexa is a seed feeding tephritid (fruit) fly which lays eggs on developing fruit and the subsequent larva of the fly will destroy the seed. The Abrostola asclepiadis is a moth whose larva also feeds on the swallow-wort causing extensive defoliation. The larva is also protected from predators due to the toxic meal it has ingested. References can be found for studies that have been done using the moth and fruit fly, under controlled conditions, as a bio-control agent for the invasive V. species where conventional control methods have been unsuccessful.
Not all of the plants on at Husrygg Nature Reserve have a poisonous nature; the orchid is non-toxic to humans and animals. Gotland and Öland have their own micro climate in the southern area of the islands; more hours of sunshine and less rain then other parts of Sweden and limestone beaches and calcareous grasslands, which many orchids favor. Of Sweden's 71 species of orchids, thirteen of those species grow only on Gotland. The tiny orchids can be elusive in the grasslands and require a sharp eye. Looking closely in the scrub grass at the reserve, only a few scattered orchids could be found.
It was mid-morning:time to leave the limestone cliffs and pebbled beach for tea,coffee and dessert at Körsbärsgården and cafe'.
Photos by George Feather and Deborah McMillin
References
Burnham, R.J. (2008-2014) “CLIMBERS: Censusing Lianas in Mesic Biomes of Eastern Regions.”
Laukkanen,Liisa, Leimu, Roosa, Muola, Anne, Lilley, Marianna, Salminen, Juha-Pekka, Mutikainen, Pia, Plant Chemistry and Local Adaptation of a Specialized Folivore Published: May 30,2012
US Food & Drug Administration Bad Bug Book