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Species
fact sheet
Yellow Centaury
Cicendia filiformis
Yellow centaury is a member of the gentian family
(Gentianaceae). It is a tiny slender plant 2-12 cm
in height with a few fleshy pinkish-green stems and
linear leaves 2-6 mm long. The terminal flowers only
open in the sun, revealing the four yellow petals
(often tinged pink).
© Hans Hillewaert under Creative Commons BY-SA licence
Lifecycle
Yellow centaury is a short-lived spring germinating
annual flowering in August and September. Seeds
require sparsely vegetated or bare ground to germinate
and plants are often present around the edge of
temporary autumn/winter pools, and can be found
in the draw-down zone around the edges during
the summer.
Habitat
It is found around seasonally-flooded pools, along
rutted trackways and on scrapes on wet grass heath
with sandy or peaty soils. More rarely, it is also present
in tightly grazed seasonally-damp acid grassland and
serpentine erosion pans, woodland rides, dune slacks
and on coastal cliffs. The key element is the open
nature of habitat with reduced competition allowing
this tiny annual to complete its life cycle.
Distribution
Yellow centaury distribution across
Britain and Ireland
The data used to create these maps has
been provided under licence from the
Botanical Society of Britain and Ireland
(BSBI) and accessed from the Society’s
online distribution database.
In England, in recent years this native species has
been restricted to heathland areas in Cornwall, Devon,
Dorset, the New Forest and the Sussex Weald. It is now
extremely rare in both Devon and Sussex and rapidly
declining in Cornwall and Dorset. The key areas for this
plant are the Lizard Peninsula and New Forest where it
is still widespread. It is also present in Wales on the
St David’s Peninsula’s grass heath commons and in
south west Ireland. Some new populations of yellow
centaury have recently been discovered in southwest England and Ireland off-setting some localised
population losses.
Species
fact sheet
Yellow Centaury
Cicendia filiformis
Habitat management for yellow centaury
GB Status and rarity
Conservation work to remove scrub along two adjacent trackways
on the Lizard Peninsula in Cornwall resulted in the re-appearance of
yellow centaury from buried seed. In 2011, these restored populations
numbered over 4000 plants. Vehicle movements creating ruts on Dowrog
Common in Pembrokeshire have also increased the habitat for this plant
where access tracks have been used to facilitate management of the
commons. Bare soil is maintained through cattle and pony grazing.
Reasons for decline
Yellow centaury is reliant on reduced competition with other plants,
which is created by winter flooding, grazing and disturbance. Lack
of management, in particular under-grazing resulting in ranker
vegetation and scrub encroachment, will threaten the survival of this
plant. Conservation should focus on reinstating extensive grazing to
wet heathland sites where the species occurs or formerly occurred,
combined with restoration and re-use of infrastructure features such as
seasonally-flooded pools and trackways.
Work should be targeted around or adjacent to surviving populations
or at historical sites where yellow centaury is no longer present as the
seed does have some longevity and may germinate once it is exposed
following conservation works.
Vehicle movements can create ruts which also help increase the habitat for this plant.
Yellow centaury is classified as
‘Nationally Scarce’ (recorded in 16-100
hectads in Great Britain) and classified
as ‘Vulnerable’ in The Vascular Plant Red
Data List for Great Britain 2005 because
of a significant decline in its area of
occupancy. It is considered to be a good
indicator species of habitat quality of
lowland acid grassland and heathland
mosaics and tends to occur with a variety
of other scarce and declining plants
including three-lobed water-crowfoot
Ranunculus tripartitus, chaffweed
Anagallis minima, allseed Radiola
linoides and pillwort Pilularia globulifera.
Historically many sites were lost due to
heathland reclamation and drainage,
though more recently cessation of grazing,
infilling of ephemeral water bodies and
upgrading of muddy trackways with
hardcore have posed greater threats. For
example, during the 1980s at least two
key trackway systems on the Lizard were
in-filled with hardcore to improve public
access removing the temporary pools
utilised by yellow centaury.
Protection under the law
This plant is included as a species “of
principal importance for the purpose of
conserving biodiversity” under Section 41
(England) of the Natural Environment and
Rural Communities Act 2006.
Survey method
Individual plants are easily identifiable
around temporary pools and a census
should be undertaken. Where a large
number of plants are present around a
particular pool the population can be
estimated. Like other annuals of this type,
populations can fluctuate greatly from
year to year with thousands of plants one
season and none in some years with less
favourable conditions. A single season’s
data is therefore unlikely to be sufficient to
judge the health of a population.
© Lauren Tucker
14 Rollestone Street,
Salisbury, Wiltshire, SP1 1DX. UK
Tel: 01722 342730
[email protected]
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