Tragopogon pratensis L., Goat's-beard

Account Summary

Growth form and preferred habitats

This distinctive annual or short-lived perennial, monocarpic, tap-rooted, leafy, 30-70 cm tall species is almost hairless and has narrow, grass-like, basal leaves with conspicuous white veins. The plant produces large, solitary, yellow flower-heads or capitula on long slender scapes, ie flowering stems that are leafless, except at their base. The florets in the capitula are overtopped by eight, slender, green bracts, twice the length of the flowers they surround and, together, they constitute a conical, one-rowed involucre that is unique and readily recognised (Perring & Walters 1989).

The lowland meadows, pastures, sand-dunes, roadside verges, hedgebanks, railway embankments and waste ground habitats T. pratensis frequents include both damp and dry, moderately fertile soils, but most generally the plant is associated with warm, sunny situations, where it has to compete with other tall herbs and grasses (Garrard & Streeter 1983; Sinker et al. 1985). In many situations, the wayside habitats it colonises remain unmown, but the species can tolerate occasional cutting.

The established strategy of T. pratensis is categorised as CR/CSR meaning it is intermediate between a Competitive-ruderal and a more balance mix of all three strategies, Competitor, Stress-tolerator and Ruderal (Grime et al. 1988, 2007).

Variation

T. pratensis is genetically rather variable and of the three recognised subspecies, it should be mentioned that in Fermanagh only subsp. minor (Mill.) Wahlenb. is present. This is the most common of the three subspecies throughout B & I and it is possibly the only one that might be native in Britain. The other two subspecies are subsp. pratensis, which is much less common, and subsp. orientalis (L.) Vollmann, a native of C & E Europe that is a rare casual alien in Britain (Garrard & Streeter 1983).

Flowering reproduction

Flowers are produced in June and July, but they only open in the mornings in sunny weather. However, the flower buds and closed mature flower-heads are such a distinctive conical shape, the species is very readily recognised even when flower-heads are closed. When the flower-heads are open, the florets are visited by numerous types of insect, chiefly bees and flies, but they will self-pollinate if all else fails (Clapham et al. 1962). After flowering, the green rays of the involucre elongate and the basal portion of each one becomes thicker until finally, in August and September, the fruiting head – like a much enlarged dandelion clock, c 10 cm in diameter – develops, and becomes broken up by the wind. The pappus head is very striking and beautiful, each long achene having an even longer slender stalk attached to the raised, feathery plume of hairs. The whole collection of achenes each with its pappus, become interlaced to form a shallow, hollow dome over the receptacle. Gerard (1597) referred to the mature fruiting flower-head as a, "downy Blowball like those of the Dandelion".

The current author (RSF) has not managed to locate any statistics of average achene production/plant, nor estimates of achene dispersal distance, although Ridley (1930) quotes Praeger (in part of the Clare Island Survey, but not properly referenced – probably the Royal Dublin Society paper on this topic, Praeger 1913b), in asserting that the time taken for Tragopogon achenes to fall 12 feet [3.65 m] in still air, is from 3 to 8 seconds, considerably faster than other plumed fruits mentioned in his survey. Obviously the theory is, the slower the fall, the greater the buoyancy in air, and therefore the greater the potential distance travelled horizontally.

The survey of soil seedbanks of NW Europe contains five estimates for T. pratensis, three of which consider it transient (ie seed surviving less than one year), while the remaining two studies believed the seed is short-term persistent (ie surviving more than one, but less than five years) (Thompson et al. 1997).

Irish occurrence

Typically, or one might even dare say, almost exclusively in Ireland, T. pratense is found amongst tall, rough grass on disturbed or somewhat neglected, waste ground near railways and major roads. Despite this habitat restriction to heavily disturbed ground, to the surprise of the current author (RSF), T. pratensis is still regarded by some botanists as native in parts of C Ireland. Scannell & Synnott (1987) treat it as native throughout the island in their Census Catalogue of the Flora of Ireland, and Webb (1977), Webb et al. (1996) and Parnell & Curtis (2012) do likewise. The BSBI New Atlas map plots some 13 Irish hectads scattered across the island as aliens, but the majority of records are accepted as native.

Writing of it in 1901, Praeger (Irish Topographical Botany, p. 201) found Goat's-beard more frequent in what he called, "middle Ireland" (ie the Central Plain), and commoner in the more densely populated east than the west of the country. He also noted that it was absent from both the north and the extreme south.

Perhaps by 1934 it was becoming more obvious to Praeger that the species was essentially dispersed by human movement, for he cites the railways in Ireland as a classic example of this anthropic or anthropophilic dispersal (ie species that are followers of man) (Featherly 1965), along with Senecio squalidus (Oxford Ragwort) travelling by rail from Cork to Dublin, and Tragopogon pratensis from Leinster to Belfast (Botanist in Ireland, paragraph 75). The high efficiency of its well-developed pappus and the suction provided by the slipstream of passing trains assisting dispersal in Co Wicklow (H20) was noted by Brunker (1950). In the 1938 FNEI 2, which Praeger co-authored with W.R. Megaw (who covered the mosses & liverworts), T. pratensis had been joined by its purple-flowered relative, T. porrifolius (Salsify) (the latter recognised in both B & I as a garden escape or relic), in colonising railway banks, often both species occurring in the same location, a situation which was also noted in the third edition of this three-county NI Flora (FNEI 3) some 50 years later.

Linnaeus, the Swedish botanist who was responsible for giving biologists the Latin binomial naming system we use today, in 1757 carried out what was probably the first scientifically produced interspecific hybrid using these two Goat's-beards (Briggs & Walters 1997). The intermediate hybrid, T. × mirabilis Rouy, is only found in Britain in a total of 26 hectads, confined to S England, very largely in the presence of both parent species (Stace et al. 2015).

In a survey of urban Belfast, Beesley & Wilde (1997) found T. pratensis in eleven 1-km squares around the city, all of which have railway lines running through them. In their Flora of Connemara and the Burren, Webb & Scannell (1983) recognised Goat's-beard as probably introduced. Here the plant is very rare and is confined to waste ground by the railway and by the roadside.

Fermanagh occurrence

T. pratensis was first recorded in Fermanagh in 1953 by the railway track beside Lough Bresk, a few kms NW of Irvinestown (Revised Typescript Flora). The three most recent records of Goat's-beard were all found by RHN within Enniskillen town. It appeared on waste ground at the Castle Redoubt in June 1978 and, then again, in successive years in rough ground on the site of the old Enniskillen railway station, no less than 40 years after it closed to traffic. There were four plants there in May 1999 and twelve in June 2000. It would be an interesting little project to investigate how the plant is reproducing and maintaining itself in this apparently very small, completely isolated urban population.

British occurrence

T. pratensis is well distributed in lowland areas throughout most of England, Wales and the S & E of Scotland. It becomes confined to coastal sites up the east of Scotland beyond Dundee and is very rare on the Scottish isles (Stroh et al. 2023). The trends in the BSBI Atlas 2020 data indicate a steady decline in T. pratensis populations in England and Wales, but better recording efforts in Scotland and Ireland, and especially so in the Republic of Ireland, show the species apparently increasing in these areas. The losses in England and Wales undoubtedly reflect the common and widespread loss of hay meadows following the switch to silage production for animal fodder from the 1950s onward (F.H. Perring and K.J. Walker, in: Stroh et al. 2023).

European and world occurrence

T. pratensis belongs to the Eurosiberian temperate phytogeographical element and has its main distribution in open grasslands throughout temperate Europe and W Asia. It has been transported by agricultural man beyond this native range northwards into Arctic Scandinavia and around the globe. T. pratensis, T. porrifolius (Salsify) and T. dubius Scop. have all been introduced to N America and become alien weeds of waste ground in 37 of the United States. In California, where all three of these Tragopogon species occur, T. pratensis is generally found in more or less "moist, disturbed places" (G.L. Stebbins, in: Hickman 1993). T. pratensis has also spread east into the Himalaya region and deep into C Asia. It has also reached New Zealand and Argentina (Hultén & Fries 1986, Map 1878).

Uses

Goat's-beard was used in medieval medicine for a bilious stomach, heartburn, or in the most desperate cases to relieve "strangury or suppression of urine" (Culpeper 1653; Grieve 1931).

The plant is perfectly edible, the tapering taproot having a sweet flavour due to its inulin content and, while young, they can be eaten raw. Older roots are best cooked like parsnips or salsify. The herb is a useful food for diabetics since inulin is composed of fructose rather than glucose units and eating it does not raise blood sugar levels. The young flowering stem, including flower buds, can be chopped into lengths, cooked and served like asparagus tips (Grieve 1931).

Names

The flowerheads of T. pratensis open at sunrise and close around mid-day, hence it is well known as a 'clock flower' and has English common names such as 'Go-to-bed-at-noon', 'Jack-go-to-bed-at-noon', 'Nap-at-noon' as well as the expected 'Twelve-o'clocks' (in Somerset) and 'Noon'. It is also referred to as 'One o'clock' in Devon and Somerset (Grigson 1955, 1987), perhaps because of the invention of British Summer Time!

The familiar name 'Goat's-beard' (or better, I believe, 'Yellow Goat's-beard') is a translation by William Turner of the shop name 'barba hirci', which links back to the 'tragopogon' in the herbal writings of Theophrastus and Dioscorides (Grigson 1955, 1987). The beard referred to is the long silky pappus of the fruiting achenes, which is also the reasoning behind the alternative name, 'Joseph's Flower', since Joseph, the Virgin's husband is always depicted as bearded in pictures of the Nativity. This latter name, together with 'Star of Jerusalem', is inked into RSF's copy of Flora Hibernica beside reference to the plant (Mackay 1836).

Threats

None.

References

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