Polemonium

This one is a Jacob's ladder (Polemonium reptans) called Stairway to Heaven.

Growing Insecurity 2010

For two or three years I do not remember to have seen it, or the seedlings, without flowers; its pretty, dwarf, rue-like foliage grew so thickly that it threatened to kill the edging of gentianella and such things as _Polemonium variegatum_, the double cuckoo-flower, and the little _Armeria setacea_; it also filled the walks, and its long wiry roots have been eradicated with difficulty.

Hardy Perennials and Old Fashioned Flowers Describing the Most Desirable Plants, for Borders, Rockeries, and Shrubberies. John Wood

The numerous species, wild and cultivated, of phlox (Fig.  118, _A_), and the blue valerian (_Polemonium_) (Fig.  118, _D_), are examples of the family _Polemoniaceæ_.

Elements of Structural and Systematic Botany For High Schools and Elementary College Courses Douglas Houghton Campbell

_Polemonium cæruleum_ is another plant very subject to this change.

Vegetable Teratology An Account of the Principal Deviations from the Usual Construction of Plants Maxwell T. Masters

Sidene, was a town called Side, which, it is believed, took the name of Polemonium in honour of Polemion, made King of Pontus by Marcus

The Catholic Encyclopedia, Volume 12: Philip II-Reuss 1840-1916 1913

_Polemonium coeruleum_, the _Veronica longifolia_, the gloxinias and others.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

_Polemonium coeruleum_ album in the neighborhood of the blue-flowered species, the distance [202] in this case being only 40 meters.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

_Polemonium dissectum_, _Salvia sylvestris_ and some others.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

In this way I obtained a hybrid between the common Jacob's ladder and the allied species _Polemonium dissectum_.

Species and Varieties, Their Origin by Mutation Hugo de Vries 1891

Polemonium, and Amisus, and Tios, and Amastris, all originally founded by the energy of the Greeks; and Cerasus, from which Lucullus brought the cherry, and two lofty islands which contain the famous cities of

The Roman History of Ammianus Marcellinus During the Reigns of the Emperors Constantius, Julian, Jovianus, Valentinian, and Valens Ammianus Marcellinus 1851