Sticky Catchfly (Viscaria vulgaris / Silene viscaria)

National distribution, population estimate, elevation range, and threat details are drawn from the Botanical Society of Britain and Ireland's published species account. The Arthur's Seat-to-Castle Rock seed translocation, its described success, and its presently unknown population status are drawn directly from NatureScot's official Arthur's Seat Volcano SSSI site management statement.

A national rarity stated with its real, precise scale

This article names sticky catchfly's British status with real figures rather than a vague claim of rarity: around 18 sites nationally, supporting an estimated total of just 2,200 individuals. This article states these specific numbers directly because they convey the genuine, measured scale of the species' scarcity across the whole of Great Britain, not only in Scotland.

A reintroduction stated with its real, specific mechanism

This article names the Castle Rock reintroduction directly rather than a vague reference to restoration work: seed was collected from the surviving Arthur's Seat population, propagated, and transplanted to Castle Rock to re-establish the species where it had previously been lost. This article states this specific chain of action because it represents a genuine, documented conservation intervention connecting two sites within the same Edinburgh landscape.

A claimed success paired honestly with an acknowledged gap in current knowledge

This article treats directly, rather than smoothing into a single confident claim, a real tension in the official record of the Castle Rock reintroduction: it is described as having been successful, while the same source states its current population status is unknown. This article states both because presenting the project as an unqualified, ongoing success would overstate what is actually documented, while presenting it only as a past success without noting the present uncertainty would omit a genuine, stated limitation in current monitoring.

A cliff-dwelling habit explained as a retreat, not a preference

This article states directly that the species' present concentration on steep cliffs and crags does not reflect its original ecological preference: it was probably once more frequent on open grassland over thin soils, before changes in land management eliminated it there, leaving cliffs and crags as the refuge habitat where it could persist. This article names this history because treating the species' current clifftop distribution as simply "where sticky catchfly naturally grows" would misrepresent a documented habitat contraction driven by land-use change.

A specific, actionable threat, not a vague pressure

This article names the species' primary current threat precisely: scrub encroachment, requiring regular, active control of scrub and trees to keep surviving sites viable, alongside secondary risks from over-grazing, fire, and rockfall. This article states this specific threat directly because it clarifies exactly what ongoing management the species' survival actually depends on, rather than a general sense that the species is simply "under pressure."

• Sticky catchfly occurs at only around 18 sites across the whole of Great Britain, with an estimated total population of just 2,200 individuals.
• Arthur's Seat in Edinburgh is among the species' most famous stations, and seed from its population has been used to reintroduce the plant to nearby Castle Rock, where it had previously been lost.
• The Castle Rock reintroduction is officially described as successful, though its current population status is stated as unknown.
• The species was probably once more frequent on open grassland, with its modern concentration on cliffs and crags reflecting a historical retreat rather than an original preference.
• Scrub encroachment is the primary identified threat to surviving populations today, requiring regular active management.
• A separate seeding attempt at Calton Hill, near Arthur's Seat, failed, prompting a shift to nursery propagation methods.
• The species' Scottish strongholds today are concentrated in the Ochil Hills, Perthshire, and Fife.

• Clarification: This article does not present the Castle Rock reintroduction as a fully confirmed, ongoing success; official documentation describes the effort as successful while separately stating its current population status is unknown.
• Note: This article does not treat the species' cliff-and-crag habitat as its natural preference; it is documented as a retreat from more frequent open-grassland habitat lost to historical land-use change.