Which Jacob’s Ladder?

Garden Jacob's Ladder, Polemonium caeruleum
The distinctive, blue flowers of Jacob’s Ladder, Polemonium caeruleum, with 5 protruding stamens and a branching style. © Karen Netto (Andrews)

The plant that I know as Jacob’s Ladder is both a wild and cultivated flowering perennial. Its wild distribution is somewhat sporadic. It also escapes from gardens to increase a naturalised presence around the country. An investigation of its name reveals some interesting regional variations. These highlight why botanical Latin is best. The single, accepted combination of genus and epithet saves confusion both regionally and internationally.


The plant is in the Polemoniaceae, Jacob’s Ladder or Phlox family. The binomial of Jacob’s Ladder is Polemonium caeruleum. Polemon was the name of a number of eminent ancient Greeks. I couldn’t find an allocation to a particular Ancient Greek, especially as Google kept turning up Pokémon in suggested search results! Caeruleum is a blue colour epithet. Stearn gives a fuller description than other sources. He describes the colour as the deep blue of the Mediterranean sky at midday. This seems an accurate given the intense blue in the photo above.

Grigson’s The Englishman’s Flora reveals that it is not just Polemonium caeruleum that is referred to as Jacob’s Ladder in some UK regions:

COMMON NAMELATIN NAMEJACOB’S LADDER REGIONS
Greater CelandineChelidonium majusShropshire
Orpine, Livelong, Midsummer MenHylotelephium telephium (syn. Sedum telephium)Kent
Solomon’s SealPolygonatum multiflorumSomerset, Wiltshire,
Berkshire & Leicestershire
Deadly NightshadeAtropa belladonnaAyrshire
Table 1: Comparison of conflicting regional common names for Jacob’s Ladder

The common name confusion is potentially fatal in the case of highly poisonous Deadly Nightshade. In the case of Solomon’s seal, Grigson reveals that an old apothecary name for the plant was scala caeli, meaning Ladder to Heaven. He also notes that our Jacob’s Ladder, Polemonium caeruleum, was known as Greek Valerian in gardens. It seems that you cannot trust plant common names to be consistent or maintain consistency nationally or regionally.

The importance of consistent plant names becomes even more apparent when you add international common names to the confusing mix. Somehow I suspect that the following list is not exhaustive. It certainly shows the importance of the work in maintaining consistent international nomenclature for accurate plant communications.

LANGUAGECOMMON NAMES
EnglishJacob’s Ladder (Devon, Sussex, East Anglia), Blue Jacket (Northern Ireland), Charity (Cumbria), Jacob’s Walking Stick (Hampshire), Ladder to Heaven (Lanarkshire), Poverty (Cumbria).
FrenchValériane grecque, Polémoine, Polémoine bleue
GermanHimmelsleiter, Sperrkraut
ItalianValeriana greca
SpanishValeriana griega
Table 2: The inconsistency of international common names for Polemonium caeruleum

Jacob’s Ladder is a biblical reference. It refers to Jacob falling asleep on a rock and dreaming of a ladder to heaven with angels.

Jacob's Ladder flowers in the garden
Jacob’s Ladder has pinnate leaves that alternate up the tall stem resembling the rungs of a ladder. © Karen Netto (Andrews)

As a West Country-born lass, Jacob’s Ladder also brings to mind two other local associations. The first Jacob’s Ladder relates to the stone steps that help tourists reach Jacob’s Tower with spectacular views over Cheddar Gorge. The other Jacob’s Ladders are stone ladders with angels on Bath Abbey.

© Karen Netto (Andrews)

References and Further Reading

Grigson, Geoffrey (1996): The Englishman’s Flora. Helicon. Oxford.

Stearn, William T. (1996): Botanical Latin. Fourth Edition. David & Charles.

Telebotanica (2020): Polemonium caeruleum L. eFlore. Last accessed 9 July 2020.

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