Wild Carrot, Daucus carota

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Wild Carrot, Daucus carota

Wild Carrot in our back garden, in the mini-meadow

Wild Carrot, Daucus carota, is another of my favourite plants. Like Alexanders, Cow Parsley, Perfoliate Alexanders, Bishop’s Flower (Ammi majus) and a host of my favourite plants, it is in the Parsley family, the Apiaceae (formerly the Umbelliferae).

Wild Carrot is a biennial herb with feathery, pinnate leaves and a pungent carroty smell when crushed. It flowers from June to September, and its mature umbels are a dull white with distinctive three-forked or pinnate lower bracts. Younger umbels usually have a pink tinge (as in the photograph above) and when mature, the flowerhead often has a single red flower in the centre. This may act as a lure for insects, signalling that the flower is worth visiting for food. Once the Wild Carrot has flowered the umbel folds inwards and the forked bracts become more obvious. The dried seedheads will often persist throughout the winter, when they look wonderful covered in frost, though they can sometimes become detached and blow around, spreading the seeds, rather like a tumbleweed. The seeds have hooked spines, which stick to animal fur and woolly socks, enabling them to be moved from place to place. See the Microscopy UK website for some lovely and fascinating photos of Wild Carrot umbels at different stages of development. Wild Carrot seeds need a period of cold to break their dormancy and so it’s best to sow them in the autumn.

There are three sub-species of Daucus carota in the British Isles. Wild Carrot, subspecies carota, is widespread in the British Isles, where it grows in grassy places on fairly infertile, well-drained, often calcareous soils. The cultivated Carrot, subspecies sativus, is cultivated and also grows in the wild as a casual on tips and as a relic of cultivation. It has the familiar swollen root. The beautiful Sea Carrot, subspecies gummifer, has stout, almost succulent stems, darker green leaves and is confined to southern and western coasts. Like Cow Parsley, Wild Carrot is also known as Queen Anne’s Lace. Other names include Birds Nest Weed, Bees’ Nest, and Devil’s Plague. The last name seems appropriate for the United States, where Wild Carrot is an introduced noxious weed. Here, the dried seed heads are sometimes considered to be a fire hazard and a threat to the honey industry. North America’s native carrot is the related Daucus pusillus (American Wild Carrot or Rattlesnake Weed).

Daucus carota subsp. gummifer

Sea Carrot, Daucus carota subsp. gummifer, on the Isles of Scilly (with a Six-spot Burnet Moth)

Wild Carrot has a spindly, forked white root, unlike the cultivated Carrot. Carrots were probably domesticated in western Asia. The Carrot Museum website gives a fascinating potted history of the process, which produced today’s fleshy, sweet, pigmented and unbranched edible root.

Carrot colour changed over the years too. The first domesticated Carrots were probably coloured purple with anthocyanins. (Dark red and purple carrots are still grown in Afghanistan today.) At some point mutations occurred to remove the purple pigmentation, resulting in white and yellow varieties of carrots. Most of today’s carrots are orange. Orange carrots are thought to date back about four hundred years. However, there is no documentary evidence to confirm the popular story that orange carrots were developed to honour the Dutch House of Orange. As the Carrot Museum website says: “The orange carrot came first – the Royal family dedication second.”

Carrots are a well-known and popular vegetable and nowadays different coloured carrots are back in fashion – yellow, white, purple with an orange core and completely purple, as well as orange, as well as rainbow seed mixtures. I grow a variety of colours on my allotment. The Plants For A Future website describes Wild Carrot roots as “thin and stringy” but the plants have a variety of medicinal uses and the seed is used as a traditional “morning after” contraceptive. (Beware that the roots of Wild Carrot can induce uterine contractions and so should not be used by pregnant women.) There are even a couple of records of phytophotodermatitis in workers canning carrots during the Second World War, by Vickers (1941) and Peck, Spolyar and Mason (1944). (See also my post on Parsnips.)

Wild Carrot flowers are attractive to many insects, including Common Red Soldier Beetles, Rhagonycha fulva (see my post on Ammi majus). In the south and south-west of England, Rose Chafers (Cetonia aurata, a beautiful, large, metallic beetle) find the flowers irresistible. In June 2010 on the Isles of Scilly I managed to take several photos of these handsome beasts.

Rose Chafers

Rose Chafers on Wild Carrot, Isles of Scilly

Purple Broomrape, Orobanche purpurea

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Yarrow Broomrape

Purple Broomrape at Beeston Regis

Sometimes, in the middle of winter, the only escape is to look forward to long summer days full of plants.

In the middle of June last year we took the train to Sheringham on the North Norfolk coast and walked to Cromer. Descending Beeston Bump we were rewarded with a new species of plant, Purple Broomrape, Orobanche purpurea. This is a very handsome beast, with dark purple flowers on a purplish brown stem. It looked very striking against the greenery of other plants, including grasses, horsetails (Equisetum), Kidney Vetch (Anthyllis vulneraria) and Yarrow.

The Yarrow (Achillea millefolium) was the reason that the Purple Broomrape was growing there. Also known as Yarrow Broomrape, Orobanche purpurea is a parasite on Yarrow.

Mistletoe, which I wrote about in December, is a hemi-parasite: although it takes some of its nutrients from its host, it possesses chlorophyll and makes its own sugars. Broomrapes are holo-parasites: they are utterly dependent on their hosts for food.

Purple Broomrape has no leaves and does not photosynthesise. It has an underground tuber and attaches to its host underground by means of haustoria. It is a member of family Orobanchaceae, which contains about 90 genera and 2000 species of herbs and shrubs distributed throughout most of the world. All, except for the genera Lindenbergia and Rehmannia, are hemi- or holo-parasites on the roots of other plants. See Wildflowers-and-Weeds.com for some lovely photographs of American members of the family.

Fourteen species of Orobanche have been recorded in the British Isles. Although “A Flora of Norfolk” (Gillian Beckett, Alec Bull & Robin Stevenson, 1999) lists five species of Orobanche in Norfolk, Hemp Broomrape (O. ramosa) was only recorded in 1880 and Greater Broomrape (O. rapum-genistae) was last seen in the county in 1986. This leaves three species: Purple Broomrape, Common Broomrape (O. minor) and Tall or Knapweed Broomrape (O. elatior). I have seen the latter once, on Marriott’s Way near Norwich, though it is more common in West Norfolk. In contrast, Common Broomrape is much more widespread and is found with a variety of host plants, including clovers (Trifolium) and various members of the Asteraceae (daisy family). Several years ago it was abundant amongst shrubs by a car park in Westwick Street in Norwich and we found it growing amongst Hyssop in Grapes Hill Community Garden in 2012.

Purple Broomrape is much rarer than its common and widespread host plant, Yarrow.  Nationally, Purple Broomrape is a plant of clifftop grasslands and, sometimes, disturbed places, on dry, slightly alkaline soils. It has the habit of disappearing for several years and then reappearing, which suggests that it can persist without flowering for many years, or has long-lived seeds. In the UK it is classed as vulnerable (see map and list of sites), but North Norfolk is one of its hotspots, along with the Isle of Wight and the Channel Islands. It can also be found on sand dunes in the Netherlands and its natural range is across Europe, as far south as Spain, Portugal and Greece, east to central Russia, the Caucasus, Asia Minor, Pakistan and India and north to Sweden. It has also been reported from Canary Islands, Morocco, and North America. (In Iran it has been recorded on a close relative of Yarrow, Achillea wilhelmsii.) However, it is endangered in much of its range as grasslands are destroyed and agriculture intensifies. The paper by Renata Piwowarczyk, “Orobanche purpurea (Orobanchaceae) in Poland: current distribution, taxonomy, plant communities, and preferred hosts” (Biodiv. Res. Conserv. 26: 73-81, 2012) gives a good, if sobering, summary.

At the time of writing, the Plants for a Future website lists ten species of Orobanche, but not O. purpurea and given its rarity it would be criminal (literally) to harvest it. Our Orobanche minor has no known edible uses, but Orobanche ammophyla is used as a food and medicine in China (mind you, so are tigers) and other edible and medicinal species include the North American Orobanche fasciculata.

If you want to see Purple Broomrape on Beeston Bump, you can follow Walk 8 in this walk leaflet. Stick to the paths and go in June or July. Last year there was lots of Purple Broomrape, but be aware that the number of flowers varies from year to year.

Mistletoe, Viscum album

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“Mistletoe,” said Luna dreamily, pointing at a large clump of white berries placed almost over Harry’s head. He jumped out from under it. “Good thinking,” said Luna seriously. “It’s often infested with nargles.” – J. K. Rowling – ‘Harry Potter and the Order of the Phoenix’.

Mistletoe

Mistletoe, Viscum album, growing in an apple tree.

It’s less than a week until Christmas, and it seems like a good idea – or at least a topical one – to write about Mistletoe, Viscum album.

Mistletoe is associated with the Winter Solstice and midwinter celebrations, specifically, the tradition of kissing under the mistletoe. Mistletoe plants are cut from trees, brought indoors and hung up. According to the WhyChristmas.com website, the original custom involved picking a berry from the sprig of Mistletoe and then kissing, until all the berries had gone. Nowadays the berries are left on the sprig, which is much more economical.

In continental Europe Mistletoe was regarded as a plant of peace and luck and in France it was often given as a Porte Bonheur (a gift for luck), at New Year, rather than Christmas.

The association between Mistletoe and kissing seems to date back to ancient beliefs about fertility, which are older than the Christian church. Mistletoe is an evergreen plant that grows mainly on deciduous host trees and provides a dramatic flush of greenery in the middle of winter amongst leafless boughs. Mistletoe’s shape may also be significant: its branches fork, it has paired leaves and its berries are full of sticky white juice – all suggestive of sexual organs in both shape and content. There are also links to the Ancient Greek story of Aeneas and the Golden Bough and the Norse legend of Baldur.

The kissing tradition may be in decline, which is a shame. A survey by a major British supermarket found that 71% of respondents under 35 had never been kissed under mistletoe, and only 14% of those surveyed had kissed under the mistletoe in the last year. But enough of kissing for now: Mistletoe is fascinating in lots of different ways.

Mistletoe, Viscum album, is a member of the Sandalwood Family, the Santalaceae. (It was previously considered to be in the family Viscaceae,  the Mistletoes.) It is a hemi-parasite. It needs to grow on a host plant for support, water and nutrients, but it has green leaves and manufactures its own sugars by photosynthesis. In the UK Mistletoe (subspecies album) can be found growing on several different tree species, including Poplars, Limes, Apple and Hawthorn. Mistletoe rarely grows on Oak, in spite of legends of druids with golden sickles gathering it from sacred oak groves, a story that seems to have originated with Pliny the Elder. In continental Europe, there are two more subspecies of Viscum album: austriacum grows on pine trees and abietis on fir trees.

Mistletoe is dioecious, with separate male and female plants. The males flower between February and April and produce clusters of insignificant flowers with four tiny petals in the fork between two branching stems. Female plants produce the familiar white berries in November and December.

Mistletoe berries are very sticky and are spread from tree to tree by birds, which eat the berries and remove the sticky seed by wiping their beaks against the bark of a tree. The scientific name of the Mistle Thrush, Turdus viscivorus, means “thrush that eats mistletoe”. Fieldfares also like the berries, but Blackcaps appear to be best at spreading them about. At one time Blackcaps were only found as summer migrants in Britain, but in recent decades continental birds spend the winter here, at the time that Mistletoe has its berries. As a result, the plant may be on the increase in the East of England. It seems to be particularly common in Common Lime and poplar trees in South Norfolk and we have some plants here in Norwich. (One can be seen when heading eastwards by train out of Norwich station; another is high on a tree on The Avenues, only hundreds of yards from my house.)

Once a Mistletoe berry has stuck to a suitable host tree, it forms a swollen holdfast. A stem and root-like haustorium grow out from the holdfast and the haustorium penetrates the host and starts to take water and minerals from its vascular tissue . Mistletoes are very highly adapted to their hemi-parasitic lifestyle. It is claimed that the germinating seeds of one species, Loranthus globosus,can ‘walk’ along a tree branch by flipping end over end until they become successfully wedged into the bark.

Mistletoe’s former stronghold was in apple growing areas along the Welsh boder, such as Herefordshire, though it has declined with the loss of our traditional orchards. Mistletoe is traditionally harvested and sold as a crop at Christmas time, and this harvest is beneficial because it stops the plant from becoming too vigorous. If left unchecked, Mistletoe reduces the productivity of its host tree, can cause stress in dry weather and may ultimately kill its host.

Mistletoe is locally common in the UK: Here are maps of Mistletoe distribution in the UK and worldwide. (The plant has been introduced to other parts of the world, including the United States.)

Worldwide, there are over a thousand species of Mistletoe and in Europe there are three more species of Mistletoe, as well as our Viscum album. The Red-berried Mistletoe, Viscum cruciatum, is found in southern Spain and grows on Olive trees, the Yellow-berried Mistletoe, Loranthus europeaus, is deciduous and grows on Oak trees and the tiny Dwarf (or Juniper) Mistletoe, Arceuthobium oxycedri, grows on Juniper. There are several North American and African species. A spectacular species from Western Australia, Nuytsia floribunda, is known locally as the Christmas Tree because it flowers in December. It grows as a free-standing tree but is nevertheless a hemi-parasite, with roots that reach out and take nutrients from nearby plants. When it grows near houses its roots will even latch onto underground electric cables and small irrigation pipes, causing damage (and even a short-circuit).

Mistletoe is poisonous to humans, though its toxicity is described as ‘slight‘ and the Plants For A Future website says that the ripe berries are edible (with caution). The active ingredients are viscotoxins and mistletoe lectins. Mistletoe poisoning can cause pale lips, inflamed eyes, dilated pupils, slow pulse, hallucinations and coma and may result in hepatitis. Mistletoe extracts have been used to treat stomach, lung and ovarian cancers and they are now marketed in Germany as ‘Iscador’ and ‘Helixor’, although their exact mechanism of action is still under investigation. Mistletoe has also been used to treat epilepsy, ulcers, high blood pressure and rheumatism and appears to have antiseptic, antispasmodic, astringent, digestive and diuretic properties.

If you want to grow your own Mistletoe, there are some great instructions and photos here.

The Mistletoe Pages website has lots and lots more information, plus free information sheets to download, posters and even a book about Mistletoe.