Scorzonera humilis
Ecology
A perennial herb of damp, unimproved grasslands and fen-meadows on relatively infertile, neutral or mildly acidic soils. Lowland.
Status
Trends
or alien. This species was first recorded in Britain at one site in Dorset in 1914. That site still supports a large population, though the field is now very overgrown. It was recorded once at another site in Dorset, in 1927. The small Warwickshire population, discovered in 1954, had gone by 1967. The two Glamorgan sites were discovered in 1996 and 1997. The native status of this species is sometimes questioned, but as its habitats are similar to those in continental Europe, most authorities accept it as native in Britain.
World Distribution
European Temperate element.
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Broad Habitats
Light (Ellenberg): 8
Moisture (Ellenberg): 7
Reaction (Ellenberg): 5
Nitrogen (Ellenberg): 2
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 4.8
July Mean Temperature (Celsius): 16.1
Annual Precipitation (mm): 1097
Height (cm): 50
Perennation - primary
Life Form - primary
Woodiness
Clonality - primary
Count of 10km squares in Great Britain: 4
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Plantatt Conservation Status
JNCC Designations
RDB Species Accounts
Scorzonera humilis L. (Asteraceae)
Viper's grass, Llys y Wiber
Status in Britain: VULNERABLE. WCA Schedule 8.
Status in Europe: Not threatened.
In Britain, native populations of S. humilis are known only at sites in Dorset and Glamorgan. It is a plant of damp lowland unimproved grassland or fen-meadow, sometimes occurring in a species-rich sward. In Glamorgan, its common associates include Carex hostiana, C. panicea, C. pulicaris, Cirsium dissectum, Juncus acutiflorus, Molinia caerulea, Potentilla erecta, Succisa pratensis, Calliergonella cuspidata and Rhytidiadelphus squarrosus. In Dorset the core of the population occurs in damp rank grassland dominated by Festuca rubra, other prominent species including Anthoxanthum odoratum, Carex nigra, Carum verticillatum, Cirsium dissectum, Holcus lanatus, Lotus corniculatus and Succisa pratensis, with sparse Molinia caerulea.
S. humilis is a perennial herb with a stout, black rootstock, broad basal leaves and one or few flowering stems. The main flowering period is from mid-May to late June with a few stragglers later in the year. Flowers are visited by bees and other insects which presumably pollinate them, but flowers may also be self-pollinated. Seed production is good: 70-80% viable seed was recorded in a sample of fruiting capitula from Glamorgan, but no seedlings were found during a search in autumn. By late August 1996 there was little evidence that S. humilis occurred in such abundance at the South Wales site, since much of the above-ground parts had disappeared through die-back and grazing. Seedling establishment is unlikely to have occurred for a number of years at the Dorset site because of the rank vegetation
S. humilis was recorded first in 1914, at Ridge, Dorset, where it still occurs in populations numbering many thousands of plants. In addition, two plants occur in a roadside ditch about 1.5 km away. At the Glamorgan site, discovered in June 1996, many thousands of plants occur over several hectares of marshy pasture enclosed in five fields near Bridgend. S. humilis was reported by L.B.Hall in the Poole Harbour area in 1927 (Druce 1929), but this site has not been refound, unless it is the same as the present roadside site. Five plants were found in 1954 in a damp meadow in the Earlswood district of Warwickshire (Hawkes & Phipps 1954), but they had gone by 1967.
The extent of the population at Ridge may have become somewhat reduced since first recorded. The site has not been grazed or cut for several years, and rank Molinia caerulea now covers about a third of the field (together with invading Carex acutiformis and Phragmites australis), with most of the S. humilis occurring in the adjacent rank Festuca rubra-Anthoxanthum odoratum dominated grassland. The Glamorgan site is extensively grazed by cattle, and rank weeds are topped if weather permits late in the year.
The status of S. humilis in Britain has been questioned, but its habitats here closely match those on the continental mainland (Hansen 1976; Wolton & Trowbridge 1990; 1992), and most authorities accept it as a true native (e.g. Druce 1929; Stace 1997).
S. humilis is of widespread occurrence in Europe, ranging from Iberia to the Balkans, southern Russia and the Caucasus, northwards to Denmark, southern Sweden, Karelia and central Russia (Hultén & Fries 1986).
J. Woodman & R. M. Walls