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Polemonium caeruleum L.

Jacob's ladder (en), Polémoine bleue (fr), Polémoine (fr), Valériane grecque (fr)

Species

Angiosperms > Ericales > Polemoniaceae > Polemonium

Characteristics

Stems erect, 30-100 cm, glabrous or sparsely glandular-pubescent above middle. Leaves pinnately compound, 7-14(-25) cm, gradually reduced upward, distal leaves ± sessile; petiole 1.5-8 cm; leaflets 11-27, ovate to lanceolate, 1-4 cm 2-14 mm, glabrous to sparsely pilose. Pedicel 3-5(-10) mm, puberulent to villous, trichomes often minutely glandular. Calyx 5-8 mm; lobes ca. as long as tube, oblong to lanceolate, apex obtuse to acuminate. Corolla violet to blue-violet, broadly campanulate, 1-2 cm; lobes obovate, margin glabrous to sparsely ciliate, apex rounded to ± acute. Stamens ca. as long as corolla, rarely shorter or longer than corolla. Style longer than stamens, slightly exserted. Capsule 5-7 mm. Seeds brown, 3-3.5 mm. Fl. Jun-Aug, fr. Jun-Sep. 2n = 14, 18 + 0-1B.
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Perennial with erect stems to c. 50 cm high; vegetative parts almost glabrous. Leaflets 18-22 (fewer in sub-floral lvs), sessile, 6-25 × 1-8 mm, linear-lanceolate or lanceolate; base broad-cuneate or rounded; apex acute. Cymes terminal, finely glandular-hairy, with up to 15 fls; lowest fls subtended by pinnate bracts with 3-7 leaflets. Pedicels usually < calyx at anthesis. Calyx 4-6 mm long; segments ovate-oblong, obtuse to subacute. Corolla ± rotate, c. 15 mm diam., white; tube c. 4 mm long; lobes rounded. Stamens with basal tuft of hairs. Style > stamens. Capsule 5-7 mm long, broad-ovoid, included in calyx tube. Seed 2.5-3 mm long, acutely 3-angled.
A related European sp. with descending rootstock or root, and at least frequently with clustered stems, occasionally escapes from cult.
Life form perennial
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination entomogamy
Spread barochory
Mature width (meter) 0.1 - 0.5
Mature height (meter) 0.5 - 0.9
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Nitrogen fixer -
Photosynthetic pathway c3

Environment

Margins of woods and swamps, by streams, especially on turf and usually in limestone hills.
Light 4-9
Soil humidity 4-7
Soil texture 2-5
Soil acidity 3-8
Soil nutriment -
Hardiness (USDA) 2-7

Usage

Uses environmental use medicinal
Edible -
Therapeutic use Cacoethes (unspecified), Sudorific (unspecified), Expectorant (unspecified), Astringent (unspecified), Cough (unspecified), Hypnotics and sedatives (unspecified), Nerve growth factors (unspecified), Wound healing (unspecified)
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by divisions or seedlings.
Mode divisions seedlings
Germination duration (days) 14 - 20
Germination temperacture (C°) 21
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -45
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Polemonium caeruleum habit picture by Andrzej Konstantynowicz (cc-by-sa)
Polemonium caeruleum habit picture by Géraldine Delatouche (cc-by-sa)
Polemonium caeruleum habit picture by Lennaert Steen (cc-by-sa)

Leaf

Polemonium caeruleum leaf picture by Dana Sukova (cc-by-sa)
Polemonium caeruleum leaf picture by Stefan Brandt (cc-by-sa)
Polemonium caeruleum leaf picture by Florence Bihet (cc-by-sa)

Flower

Polemonium caeruleum flower picture by Ron (cc-by-sa)
Polemonium caeruleum flower picture by stan wtever (cc-by-sa)
Polemonium caeruleum flower picture by Dana Sukova (cc-by-sa)

Distribution

Polemonium caeruleum world distribution map, present in Canada, China, France, United Kingdom of Great Britain and Northern Ireland, Liberia, New Zealand, Pakistan, and United States of America

Identifiers

LSID urn:lsid:ipni.org:names:689911-1
WFO ID wfo-0000484167
COL ID 4KXG7
BDTFX ID 51071
INPN ID 114480
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Polemonium sibiricum Polemonium frolovianum Polemonium gracile Polemonium dissectum Polemonium vulgare Polemonium lacteum Polemonium lanatum Polemonium album Polemonium caeruleum subsp. caeruleum Polemonium caeruleum var. lusus Polemonium caeruleum var. caeruleum Polemonium caeruleum

Lower taxons

Polemonium caeruleum subsp. himalayanum Polemonium caeruleum var. nipponicum
WorldFloraDB 2024