Blue Jacob's ladder Polemonium caeruleum
© Science & Society
Blue Jacob's ladder, Polemonium caeruleum. Handcoloured copperplate engraving by Charles Mathews of a drawing by Isaac Russell from William Baxter's British Phaenogamous Botany 1835. Scotsman William Baxter (1788-1871) was the curator of the Oxford Botanic Garden from 1813 to 1854.